Strategies and Solutions to Advanced Organic Reaction Mechanisms

1. Cover image - p. iv 2. Title page - p. iv 3. Table of Contents - p. iv 4. Copyright - p. iv 5. Dedication - p. v 6. Preface - p. ix 7. Chapter 1: The Logic of Organic Reaction Mechanisms - p. xiv 8. Chapter 2: Evidence for Organic Reaction Mechanisms - p. 16 9. Chapter 3: Problem Solving Organic Reaction Mechanisms - p. 29 10. Chapter 4: Solutions 1 – 50 - p. 41 11. Question 1 A Tandem Route to 1,2,3,4-Tetrasubstituted Naphthalenes - p. 43 12. Solution: 1 to 2 - p. 43 13. Solution: 2 to 3 - p. 44 14. Solution: D to 4 - p. 44 15. Balanced chemical equations - p. 44 16. Key Steps Explained - p. 45 17. Additional Resources - p. 45 18. Question 2 Hydroazulenes by Radical Cyclization - p. 46 19. Solution - p. 46 20. Balanced chemical equation - p. 47 21. Key Steps Explained - p. 47 22. Additional Resources - p. 47 23. Question 3 Cinnolines to Indoles - p. 48 24. Solution - p. 48 25. Balanced Chemical Equation - p. 48 26. Key Steps Explained - p. 49 27. Additional Resources - p. 50 28. Question 4 Rearrangement During NMR Studies - p. 51 29. Solution - p. 51 30. Key Steps Explained - p. 52 31. Additional Resources - p. 52 32. Question 5 Synthesis of Trifluoromethyl Heterocycles - p. 53 33. Solution: 1 to 2 - p. 53 34. Solution: 2 to 3 - p. 54 35. Solution: 3 to 4 - p. 54 36. Balanced Chemical Equations - p. 54 37. Key Steps Explained - p. 55 38. Additional Resources - p. 55 39. Question 6 3-Substituted Chromones From Pyranobenzopyrans - p. 56 40. Solution - p. 56 41. Balanced Chemical Equation - p. 56 42. Key Steps Explained - p. 57 43. Additional Resources - p. 57 44. Question 7 Acid-Catalyzed Rearrangements of 1-Arylindoles - p. 57 45. Solution: 1 to 2 - p. 58 46. Balanced Chemical Equation - p. 58 47. Key Steps Explained - p. 59 48. Additional Resources - p. 60 49. Question 8 An Unusual Deprotection of an Aryl Ester - p. 60 50. Solution: 2 to 3 - p. 61 51. Balanced Chemical Equation - p. 61 52. Key Steps Explained - p. 61 53. Additional Resources - p. 62 54. Question 9 3,1-Benzoxathiin Formation - p. 63 55. Solution: Mechanism 1 - p. 63 56. Solution: Mechanism 2 - p. 63 57. Key Steps Explained - p. 64 58. Additional Resources - p. 65 59. Question 10 Arylacetone Synthesis by Carroll-Type Rearrangement - p. 65 60. Solution: 1 and 2 to 3 - p. 66 61. Solution: 3 to 4 - p. 66 62. Key Steps Explained - p. 66 63. Additional Resources - p. 67 64. Question 11 Attempted Knoevenagel Reaction Gives Mannich-Type Products - p. 67 65. Solution: 1 to 2 - p. 68 66. Balanced Chemical Equation: 1 to 2 - p. 69 67. Solution: 3 to 2 - p. 69 68. Balanced Chemical Equation: 3 to 2 - p. 69 69. Key Steps Explained - p. 69 70. Additional Resources - p. 70 71. Question 12 Pyridinium Salt Rearrangements - p. 70 72. Solution: 1 to 2 - p. 70 73. Solution: 3 to 4 - p. 71 74. Balanced Chemical Equations - p. 72 75. Key Steps Explained - p. 72 76. Additional Resources - p. 76 77. Question 13 A Pyridazine From a Thiophene Dioxide - p. 77 78. Solution: 1 and 2 to 3 - p. 77 79. Solution: 3 to 4 - p. 78 80. Balanced Chemical Equations - p. 78 81. Key Steps Explained - p. 78 82. Additional Resources - p. 79 83. Question 14 Biomimetic Synthesis of Litebamine - p. 80 84. Solution: 1 to 2 - p. 80 85. Balanced Chemical Equation: 1 to 2 - p. 81 86. Solution: 4 to 5 - p. 81 87. Solution: 5 to 6 - p. 81 88. Balanced Chemical Equation: 5 to 6 - p. 82 89. Key Steps Explained - p. 82 90. Additional Resources - p. 83 91. Question 15 Acid-Catalyzed Degradation of N-Nitroso-2,3-didehydromorpholine - p. 83 92. Solution - p. 84 93. Balanced Chemical Equation - p. 84 94. Key Steps Explained - p. 84 95. Additional Resources - p. 86 96. Question 16 A New Route to 4-Amino-3-arylcinnolines - p. 87 97. Solution: 2 to 3 (Path a) - p. 87 98. Solution: 2 to 3 (Path b) - p. 88 99. Balanced Chemical Equation - p. 88 100. Key Steps Explained - p. 88 101. Additional Resources - p. 88 102. Question 17 Base-Induced Cyclizations of o-Ethynylaryl-Substituted Benzyl Alcohols - p. 89 103. Solution: 1 to 2 - p. 89 104. Solution: 3 to 5 - p. 89 105. Key Steps Explained - p. 90 106. Additional Resources - p. 91 107. Question 18 Trifluoromethylpyrroles From Trifluoromethyloxazolones - p. 92 108. Solution - p. 92 109. Balanced Chemical Equation - p. 92 110. Key Steps Explained - p. 92 111. Additional Resources - p. 93 112. Question 19 The Hooker Oxidation - p. 93 113. Solution - p. 93 114. Balanced Chemical Equation - p. 94 115. Key Steps Explained - p. 94 116. Additional Resources - p. 98 117. Question 20 Synthesis of 1,3-Disubstituted Pyrroles - p. 98 118. Solution: 3 to 4 - p. 99 119. Balanced Chemical Equation - p. 99 120. Key Steps Explained - p. 99 121. Additional Resources - p. 100 122. Question 21 Grob Fragmentation of a 1-Azaadamantane - p. 100 123. Solution: 1 to 2 - p. 101 124. Balanced Chemical Equation - p. 101 125. Solution: 2 to 3 - p. 101 126. Balanced Chemical Equation - p. 102 127. Key Steps Explained - p. 102 128. Additional Resources - p. 102 129. Question 22 Selective Substitution of 3-Methoxypyrazine N-Oxide - p. 102 130. Solution: 1, 2, and 3 to 4 (When ZnBr2 Present) - p. 103 131. Balanced Chemical Equation - p. 103 132. Key Steps Explained - p. 103 133. Additional Resources - p. 106 134. Question 23 Reactions of Ethacrylate Esters With NO2BF4 - p. 107 135. Solution: 1 to 2 - p. 107 136. Solution: A to 3 - p. 107 137. Solution: 4 to 5 - p. 108 138. Balanced Chemical Equation: 4 to 5 - p. 108 139. Solution: C to 6 - p. 108 140. Balanced Chemical Equation: 4 to 6 - p. 108 141. Key Steps Explained - p. 108 142. Additional Resources - p. 111 143. Question 24 A Furan Synthesis - p. 112 144. Solution: 1 to 2 - p. 112 145. Solution: 2 to 3 (Authors’ Mechanism) - p. 112 146. Balanced Chemical Equations - p. 113 147. Key Steps Explained - p. 113 148. Additional Resources - p. 114 149. Question 25 Dimerization of Vinca Alkaloids - p. 115 150. Solution - p. 115 151. Key Steps Explained - p. 116 152. Additional Resources - p. 116 153. Question 26 Nitration of a Quinoline Derivative - p. 116 154. Solution - p. 117 155. Balanced Chemical Equation - p. 118 156. Key Steps Explained - p. 118 157. Additional Resources - p. 118 158. Question 27 Synthesis of Binaphthyldiquinones - p. 119 159. Solution - p. 119 160. Balanced Chemical Equation - p. 119 161. Key Steps Explained - p. 120 162. Additional Resources - p. 120 163. Question 28 Heterocyclic Fun With DMAD - p. 120 164. Solution: Mechanism 1 - p. 121 165. Solution: Mechanism 2 - p. 121 166. Balanced Chemical Equation - p. 122 167. Key Steps Explained - p. 122 168. Additional Resources - p. 122 169. Question 29 Unexpected Formation of a 1,5-Benzodiazonine - p. 123 170. Solution - p. 123 171. Balanced Chemical Equation - p. 124 172. Key Steps Explained - p. 124 173. Additional Resources - p. 125 174. Question 30 A Thiopyran to Thiophene Transformation - p. 125 175. Solution: 1 to 2 - p. 126 176. Solution: 3 to 4 (Path a: F to 4) - p. 126 177. Solution: 3 to 4 (Path b: F to 4) - p. 127 178. Balanced Chemical Equations - p. 127 179. Key Steps Explained - p. 127 180. Additional Resources - p. 129 181. Question 31 Skeletal Rearrangements of a Diterpene - p. 129 182. Solution: 1 to 2 - p. 129 183. Solution: B to 4 - p. 130 184. Solution: 4 to 3 - p. 130 185. Solution: 3 to 5 - p. 130 186. Balanced Chemical Equations - p. 131 187. Key Steps Explained - p. 131 188. Additional Resources - p. 132 189. Question 32 Reissert Reactions of Quinoxaline N-Oxides - p. 132 190. Solution: 1 to 2 - p. 133 191. Solution: 1 to 3 - p. 133 192. Solution: 4 to 5 - p. 134 193. Balanced Chemical Equations - p. 134 194. Key Steps Explained - p. 134 195. Additional Resources - p. 135 196. Question 33 Unexpected Results in Directed Metalation - p. 135 197. Solution: 3 to 4/5 - p. 136 198. Key Steps Explained - p. 136 199. Additional Resources - p. 137 200. Question 34 1,4-Dioxene in Synthesis - p. 138 201. Solution - p. 139 202. Balanced Chemical Equation - p. 139 203. Key Steps Explained - p. 139 204. Additional Resources - p. 140 205. Question 35 Collins Oxidation of Phenylethanols - p. 140 206. Solution: 1 to 2 - p. 141 207. Solution: 4 to 5 - p. 141 208. Balanced Chemical Equations - p. 142 209. Key Steps Explained - p. 142 210. Additional Resources - p. 143 211. Question 36 Allene Sulfoxide Rearrangement - p. 144 212. Solution: 2 to 3 - p. 144 213. Solution: 3 to 4 - p. 145 214. Balanced Chemical Equations - p. 145 215. Key Steps Explained - p. 145 216. Additional Resources - p. 146 217. Question 37 A Failed “Pinacol-Type” Rearrangement - p. 146 218. Solution - p. 147 219. Balanced Chemical Equation - p. 147 220. Key Steps Explained - p. 148 221. Additional Resources - p. 148 222. Question 38 Allylation of 1,4-Benzoquinones - p. 148 223. Solution - p. 149 224. Balanced Chemical Equation - p. 149 225. Key Steps Explained - p. 150 226. Additional Resources - p. 150 227. Question 39 Benzopyrene Synthesis—By Accident - p. 150 228. Solution - p. 150 229. Balanced Chemical Equation - p. 151 230. Key Steps Explained - p. 151 231. Additional Resources - p. 152 232. Question 40 Rearrangement of Ketene Acetals - p. 153 233. Solution: 2E to 3 - p. 153 234. Solution: 2Z to 3 - p. 154 235. Balanced Chemical Equation - p. 154 236. Key Steps Explained - p. 154 237. Additional Resources - p. 155 238. Question 41 Nucleophilic Additions to a Heterocyclic o-Quinone - p. 156 239. Solution: 1 to 2 - p. 156 240. Solution: 1 to 3 - p. 157 241. Key Steps Explained - p. 157 242. Additional Resources - p. 158 243. Question 42 How Mitomycin C Can Crosslink DNA - p. 159 244. Solution - p. 159 245. Balanced Chemical Equation - p. 160 246. Key Steps Explained - p. 160 247. Additional Resources - p. 161 248. Question 43 Two Carbon Ring Expansions of Cycloalkanones - p. 161 249. Solution: 1 to 2 - p. 162 250. Balanced Chemical Equation: 1 to 2 - p. 162 251. Solution: 3 to 4 - p. 162 252. Balanced Chemical Equation: 3 to 4 - p. 163 253. Solution: 3 to 5 - p. 163 254. Balanced Chemical Equation: 3 to 5 - p. 163 255. Key Steps Explained - p. 164 256. Additional Resources - p. 166 257. Question 44 Fulgides: Synthesis and Photochromism - p. 167 258. Solution: 1 and 2 to 3 (Stobbe Condensation) - p. 168 259. Balanced Chemical Equation: 1 and 2 to 3 - p. 168 260. Solution: 3 to 4 (Lactone Opening Esterification) - p. 168 261. Balanced Chemical Equation: 3 to 4 - p. 168 262. Solution: 4 to 5 (Stobbe Condensation) - p. 169 263. Balanced Chemical Equation: 4 to 5 - p. 169 264. Solution: 5 to 6 (Saponification of Diester to Diacid) - p. 169 265. Balanced Chemical Equation: 5 to 6 - p. 169 266. Solution: 6 to 7 - p. 170 267. Balanced Chemical Equation: 6 to 7 - p. 170 268. Solution: 7 to 8 (Base-Assisted Ring Opening Alkylation) - p. 170 269. Balanced Chemical Equation: 7 to 8 - p. 171 270. Solution: 8 to 9 (Acetyl Chloride-Assisted Cyclization) - p. 171 271. Balanced Chemical Equation: 8 to 9 - p. 171 272. Solution: 9 to 10 (Photochromism Mechanism) - p. 171 273. Key Steps Explained - p. 172 274. Additional Resources - p. 172 275. Question 45 Benzodiazepines From (R)-(+)-Pulegone - p. 172 276. Solution - p. 173 277. Key Steps Explained - p. 173 278. Additional Resources - p. 173 279. Question 46 A Furan to Pyran Ring Expansion - p. 174 280. Solution: 1 to 2 (Mechanism 1: Consistent With Deuterium Labeling Study) - p. 174 281. Solution: 1 to 2 (Mechanism 2: Inconsistent With Deuterium Labeling Study) - p. 175 282. Key Steps Explained - p. 175 283. Question 47 A Structure and Mechanism Correction - p. 178 284. Solution: 1 and 2 to 3 (Claimed Reaction) - p. 179 285. Solution: 3 to 4 (Claimed Reaction) - p. 179 286. Solution: 1 and 2 to 5 (Actual Reaction) - p. 179 287. Solution: 5 to 4 (Actual Reaction) - p. 180 288. Balanced Chemical Equations - p. 180 289. Key Steps Explained - p. 181 290. Additional Resources - p. 181 291. Question 48 Propargylbenzotriazoles to Five-membered Heterocycles - p. 182 292. Solution: 1 and 2 to 3 - p. 182 293. Balanced Chemical Equation: 1 and 2 to 3 - p. 183 294. Solution: 3 to 4 - p. 183 295. Balanced Chemical Equation: 3 to 4 - p. 183 296. Key Steps Explained - p. 183 297. Additional Resources - p. 184 298. Question 49 From Carvone to an Isoxazoloazepine - p. 184 299. Solution - p. 184 300. Balanced Chemical Equation - p. 185 301. Key Steps Explained - p. 185 302. Additional Resources - p. 185 303. Question 50 Isoxazoles From Cyclopropanes - p. 186 304. Solution: 1 to 2 - p. 186 305. Balanced Chemical Equation - p. 187 306. Key Steps Explained - p. 187 307. Additional Resources - p. 187 308. Chapter 5: Solutions 51 – 100 - p. 187 309. Question 51 A Radical Cascade From a Ketene Dithioacetal - p. 189 310. Solution - p. 189 311. Balanced Chemical Equation - p. 190 312. Key Steps Explained - p. 190 313. Additional Resources - p. 190 314. Question 52 A Synthesis of 3-Alkyl-1-naphthols - p. 190 315. Solution: 2 to 3 - p. 191 316. Solution: 4 to 5 - p. 192 317. Solution: 6 to 7 - p. 192 318. Key Steps Explained - p. 192 319. Additional Resources - p. 193 320. Question 53 An Entry to Indole Alkaloids of Unusual Structural Type - p. 194 321. Solution: 1 to 2 - p. 194 322. Solution: 2 to 3 - p. 194 323. Solution: 3 to 5 and 4 - p. 194 324. Balanced Chemical Equations - p. 194 325. Key Steps Explained - p. 197 326. Additional Resources - p. 197 327. Question 54 Cyclization as a Key Step to Hirsutene - p. 198 328. Solution - p. 198 329. Key Steps Explained - p. 199 330. Additional Resources - p. 199 331. Question 55 A 1,3-Cyclopentanedione to 1,4-Cyclohexanedione Transformation - p. 199 332. Solution: Originally Proposed Mechanism for 1 to 2 - p. 200 333. Solution: Revised Mechanism for 1 to 2 Part 1: 1 to 3 - p. 200 334. Solution: Revised Mechanism for 1 to 2 Part 2: 3 to 2 - p. 201 335. Key Steps Explained - p. 201 336. Additional Resources - p. 201 337. Question 56 Conversion of o-Hydroxyaryl Ketones Into 1,2-Diacylbenzenes - p. 202 338. Solution - p. 202 339. Balanced Chemical Equation - p. 203 340. Key Steps Explained - p. 203 341. Additional Resources - p. 204 342. Question 57 Mechanisms of Bimane Formation - p. 205 343. Solution: 1 to syn-2 - p. 206 344. Solution: A and B to anti-2 - p. 206 345. Balanced Chemical Equation: 1 to syn-2/anti-2 - p. 206 346. Solution: 3 to syn-4 - p. 206 347. Balanced Chemical Equation: 3 to syn-4 - p. 207 348. Key Steps Explained - p. 207 349. Additional Resources - p. 210 350. Question 58 A Carbohydrate to Cyclopentanol Conversion - p. 210 351. Solution - p. 211 352. Balanced Chemical Equation - p. 211 353. Key Steps Explained - p. 212 354. Balanced Chemical Equation: Scheme 2 - p. 213 355. Balanced Chemical Equation: Scheme 3 - p. 214 356. Balanced Chemical Equation: Scheme 4 - p. 215 357. Additional Resources - p. 215 358. Question 59 Pyridazines From 1,2,4-Triazines - p. 215 359. Solution: 1 to 2 Using 15N Label on Phenylacetonitrile - p. 216 360. Solution: 2 to 3 Using 15N Label on Phenylacetonitrile - p. 216 361. Balanced Chemical Equations - p. 216 362. Key Steps Explained - p. 216 363. Additional Resources - p. 218 364. Question 60 Natural Product Degradation During Extraction and/or Chromatography - p. 218 365. Solution: Author’s Proposal (Ionic Mechanism) - p. 219 366. Solution: Alternative Proposal (Radical Mechanism) - p. 219 367. Balanced Chemical Equation - p. 219 368. Key Steps Explained - p. 219 369. Additional Resources - p. 220 370. Question 61 Simple Access to Oxaadamantanes - p. 220 371. Solution: 1 to 2 - p. 220 372. Balanced Chemical Equation: 1 to 2 - p. 220 373. Solution: I to 3 - p. 220 374. Balanced Chemical Equation: 1 to 3 - p. 222 375. Solution: D to 4 - p. 222 376. Balanced Chemical Equation: 1 to 4 - p. 222 377. Key Steps Explained - p. 222 378. Additional Resources - p. 228 379. Question 62 A Pyrimidine Rearrangement - p. 228 380. Solution - p. 228 381. Balanced Chemical Equation - p. 229 382. Key Steps Explained - p. 229 383. Additional Resources - p. 229 384. Question 63 1,4-Thiazin-3-ones From 1,4-Oxathiins - p. 230 385. Solution - p. 230 386. Balanced Chemical Equation - p. 231 387. Key Steps Explained - p. 231 388. Additional Resources - p. 231 389. Question 64 An Unusual Route to 3-Acylfurans - p. 232 390. Solution: 1 to 2 - p. 232 391. Solution: 2 to 3 - p. 232 392. Balanced Chemical Equations - p. 233 393. Key Steps Explained - p. 233 394. Additional Resources - p. 233 395. Question 65 Reaction of PQQ With l-Tryptophan - p. 233 396. Solution - p. 234 397. Additional Resources - p. 243 398. Question 66 An Unexpected Result From an Attempted Double Bischler-Napieralski Reaction - p. 243 399. Solution - p. 244 400. Balanced Chemical Equation - p. 245 401. Key Steps Explained - p. 245 402. Additional Resources - p. 247 403. Question 67 Bis-Indole Alkaloid Formation - p. 247 404. Solution: 1 to 2 - p. 248 405. Solution: 3 to 4 and 5 - p. 248 406. Solution: 6 to 7 and 8 - p. 249 407. Balanced Chemical Equations - p. 250 408. Key Steps Explained - p. 250 409. Additional Resources - p. 251 410. Question 68 Azaphenalene Alkaloid Synthesis: A Key Step - p. 251 411. Solution: Path A - p. 252 412. Solution: Path B (C to 2 Alternative) - p. 252 413. Balanced Chemical Equation - p. 252 414. Key Steps Explained - p. 253 415. Additional Resources - p. 253 416. Question 69 A Primary Nitroalkane to Carboxylic Acid Transformation - p. 254 417. Solution: 1 to 2 - p. 254 418. Solution: 3 to 2 - p. 254 419. Balanced Chemical Equations - p. 254 420. Key Steps Explained - p. 256 421. Additional Resources - p. 257 422. Question 70 α-Diazoketones With Rhodium(II) Acetate - p. 257 423. Solution: 1 to 2 - p. 258 424. Solution: E to 3 - p. 258 425. Solution: C to J and 4 - p. 258 426. Balanced Chemical Equations - p. 259 427. Key Steps Explained - p. 259 428. Additional Resources - p. 259 429. Question 71 Pyrrolo[1,2-a]benzimidazole Synthesis by Ortho Nitro Interaction - p. 261 430. Solution: 1 to 2 - p. 261 431. Solution: H to 3 - p. 261 432. Solution: H to 4 - p. 261 433. Balanced Chemical Equations - p. 263 434. Key Steps Explained - p. 263 435. Additional Resources - p. 264 436. Question 72 Horner-Wittig Reaction on a Bifuranylidenedione - p. 264 437. Solution: 1 and 2 to 3 - p. 265 438. Solution: 3 to 4 - p. 265 439. Balanced Chemical Equations - p. 266 440. Key Steps Explained - p. 266 441. Additional Resources - p. 266 442. Question 73 Lactone Ammonolysis - p. 267 443. Solution - p. 267 444. Balanced Chemical Equation - p. 268 445. Key Steps Explained - p. 268 446. Additional Resources - p. 270 447. Question 74 Intramolecular Schmidt Reaction - p. 270 448. Solution - p. 271 449. Balanced Chemical Equation - p. 271 450. Key Steps Explained - p. 271 451. Additional Resources - p. 271 452. Question 75 Indolizidones by Intermolecular Photochemical Reaction - p. 272 453. Solution: 1 to E - p. 272 454. Solution: E to G - p. 273 455. Solution: G to 3 (Author Mechanism) - p. 273 456. Solution: G to 3 (Alternative Proposal) - p. 273 457. Balanced Chemical Equations - p. 273 458. Key Steps Explained - p. 274 459. Additional Resources - p. 275 460. Question 76 An Unexpected Product From Amine Oxidation - p. 275 461. Solution - p. 275 462. Balanced Chemical Equation - p. 276 463. Key Steps Explained - p. 276 464. Additional Resources - p. 277 465. Question 77 Degradation of Pyripyropene A - p. 277 466. Solution: 1 to 2 - p. 278 467. Balanced Chemical Equation: 1 to 2 - p. 278 468. Solution: 2 to 3 and 4 - p. 279 469. Balanced Chemical Equation: 2 to 3 and 4 - p. 279 470. Key Steps Explained - p. 279 471. Additional Resources - p. 281 472. Question 78 Benzofurans From Cyclobutenediones - p. 281 473. Solution: 1 and 2 to 3 - p. 282 474. Solution: 3 to 4 - p. 282 475. Solution: 4 to 5 - p. 283 476. Solution: 5 to 6 - p. 283 477. Balanced Chemical Equations - p. 283 478. Key Steps Explained - p. 283 479. Additional Resources - p. 285 480. Question 79 Acid-Catalyzed Condensation of Indole With Acetone - p. 286 481. Solution - p. 286 482. Balanced Chemical Equation - p. 286 483. Key Steps Explained - p. 288 484. Additional Resources - p. 288 485. Question 80 A Synthesis of 2-Formylpyrrolidines - p. 288 486. Solution: 1 to 2 - p. 289 487. Solution: 2 to 3 - p. 289 488. Balanced Chemical Equation: 2 to 3 - p. 289 489. Solution: 3 to 4 - p. 289 490. Key Steps Explained - p. 290 491. Additional Resources - p. 290 492. Question 81 An Abnormal Claisen Rearrangement - p. 291 493. Solution - p. 291 494. Key Steps Explained - p. 291 495. Additional Resources - p. 292 496. Question 82 Benzoxepinones From Phthalides - p. 293 497. Solution - p. 293 498. Balanced Chemical Equation - p. 293 499. Key Steps Explained - p. 294 500. Additional Resources - p. 294 501. Question 83 m-Terphenyls From Pyrones - p. 294 502. Solution: 1 to 2 - p. 294 503. Solution: B to 3 - p. 295 504. Balanced Chemical Equations - p. 295 505. Key Steps Explained - p. 295 506. Additional Resources - p. 296 507. Question 84 A Cascade Reaction - p. 296 508. Solution - p. 297 509. Balanced Chemical Equation - p. 297 510. Key Steps Explained - p. 297 511. Additional Resources - p. 298 512. Question 85 Photochemical Ortho Rearrangements - p. 298 513. Solution: 1 to 3 - p. 299 514. Balanced Chemical Equations - p. 299 515. Key Steps Explained - p. 299 516. Additional Resources - p. 300 517. Question 86 From Bicycle to Pentacycle to Tricycle - p. 301 518. Solution: 1 and 2 to 3 - p. 301 519. Solution: 3 to 4 - p. 301 520. Balanced Chemical Equation - p. 301 521. Key Steps Explained - p. 301 522. Additional Resources - p. 305 523. Question 87 Lewis Acid-Catalyzed Cyclopropyl Ketone Rearrangement - p. 306 524. Solution - p. 306 525. Key Steps Explained - p. 306 526. Additional Resources - p. 306 527. Question 88 An Intramolecular Ring Closure - p. 308 528. Solution - p. 308 529. Balanced Chemical Equation - p. 308 530. Key Steps Explained - p. 308 531. Additional Resources - p. 310 532. Question 89 Photochemical Rearrangement of Pyran-2-ones - p. 310 533. Solution: 1 to 2 - p. 311 534. Solution: F to H (Alternative Path) - p. 311 535. Key Steps Explained - p. 312 536. Additional Resources - p. 312 537. Question 90 A Paclitaxel Rearrangement - p. 312 538. Solution - p. 313 539. Balanced Chemical Equation - p. 313 540. Key Steps Explained - p. 313 541. Additional Resources - p. 314 542. Question 91 An Ionic Diels-Alder Reaction - p. 314 543. Solution - p. 314 544. Balanced Chemical Equation - p. 315 545. Key Steps Explained - p. 315 546. Additional Resources - p. 315 547. Question 92 The Eschenmoser Fragmentation Reaction Extended - p. 316 548. Solution - p. 316 549. Balanced Chemical Equation - p. 317 550. Key Steps Explained - p. 317 551. Additional Resources - p. 318 552. Question 93 A Modified Batcho-Leimgruber Synthesis - p. 319 553. Solution: 1 to 4 p-TsOH Acid Catalysis - p. 320 554. Key Steps Explained - p. 320 555. Additional Resources - p. 322 556. Question 94 A Pyrone to Pyran Conversion - p. 322 557. Solution - p. 323 558. Balanced Chemical Equation - p. 323 559. Key Steps Explained - p. 323 560. Additional Resources - p. 324 561. Question 95 Conformationally Rigid 4-Oxoquinolines - p. 325 562. Solution - p. 325 563. Balanced Chemical Equation - p. 325 564. Key Steps Explained - p. 325 565. Additional Resources - p. 327 566. Question 96 An Efficient Chromene Synthesis - p. 327 567. Solution: 1 and 2 to 3 - p. 328 568. Solution: 3 to 4 - p. 328 569. Balanced Chemical Equations - p. 328 570. Key Steps Explained - p. 329 571. Additional Resources - p. 329 572. Question 97 Flash Vacuum Pyrolysis of o-Xylylene Dimers - p. 329 573. Solution: 1 to 2 - p. 330 574. Solution: 3 to 4 - p. 330 575. Key Steps Explained - p. 331 576. Additional Resources - p. 331 577. Question 98 Synthesis of a Neocarzinostatin Building Block - p. 331 578. Solution - p. 332 579. Key Steps Explained - p. 332 580. Additional Resources - p. 332 581. Question 99 Oxazole Esters From α-Amino Acids - p. 332 582. Solution - p. 333 583. Balanced Chemical Equation - p. 333 584. Key Steps Explained - p. 334 585. Additional Resources - p. 334 586. Question 100 Unexpected Formation of a Phenazine - p. 334 587. Solution - p. 335 588. Balanced Chemical Equation - p. 336 589. Key Steps Explained - p. 336 590. Additional Resources - p. 336 591. Chapter 6: Solutions 101 – 150 - p. 336 592. Question 101 Conversion of Primary Amides Into Nitriles - p. 337 593. Solution - p. 337 594. Balanced Chemical Equation - p. 338 595. Key Steps Explained - p. 338 596. Additional Resources - p. 339 597. Question 102 An Efficient Benzo[b]fluorene Synthesis - p. 339 598. Solution - p. 340 599. Balanced Chemical Equation - p. 341 600. Key Steps Explained - p. 341 601. Additional Resources - p. 341 602. Question 103 A Facile Synthesis of Tetracyclic Pyrroloquinazolines - p. 341 603. Solution - p. 342 604. Balanced Chemical Equation - p. 342 605. Key Steps Explained - p. 343 606. Additional Resources - p. 343 607. Question 104 Ethyl 2-Chloronicotinate From Acyclic Precursors - p. 343 608. Solution: 1, 2, and 3 to 4 - p. 343 609. Solution: 4 to 5 - p. 344 610. Balanced Chemical Equation: 1, 2, and 3 to 4 - p. 344 611. Balanced Chemical Equation: 4 to 5 - p. 345 612. Key Steps Explained - p. 345 613. Additional Resources - p. 345 614. Question 105 A 2-Arylpropanoic Acid Synthesis - p. 345 615. Solution: 1 to 2 - p. 346 616. Solution: 2 to 3 - p. 346 617. Solution: 3 to 4 - p. 347 618. Balanced Chemical Equations - p. 347 619. Key Steps Explained - p. 347 620. Additional Resources - p. 348 621. Question 106 Synthesis of Isoquinolin-4-ones - p. 348 622. Solution: 1 to 2 - p. 348 623. Solution: 1 to 3 - p. 349 624. Key Steps Explained - p. 349 625. Additional Resources - p. 349 626. Question 107 Naphthopyrandione From 1,4-Naphthoquinone - p. 350 627. Solution: 1a to 3 - p. 350 628. Solution: 1b to 4 - p. 351 629. Balanced Chemical Equations - p. 351 630. Key Steps Explained - p. 351 631. Question 108 A Photochromic Product for Sunglasses - p. 355 632. Solution: 1 to 2 - p. 355 633. Solution: 2 to 3 - p. 355 634. Balanced Chemical Equations - p. 355 635. Key Steps Explained - p. 355 636. Additional Resources - p. 357 637. Question 109 A Quick Entry to the Aklavinone Ring System - p. 357 638. Solution - p. 357 639. Balanced Chemical Equation - p. 357 640. Key Steps Explained - p. 357 641. Additional Resources - p. 357 642. Question 110 A “Stable Enol” That Doesn’t Exist - p. 359 643. Solution - p. 359 644. Balanced Chemical Equation - p. 359 645. Key Steps Explained - p. 359 646. Additional Resources - p. 361 647. Question 111 Conversion of an Indole-Based Bicyclo[5.3.1]undecane Into a Bicyclo[5.4.0]undecane - p. 362 648. Solution - p. 362 649. Balanced Chemical Equation - p. 363 650. Key Steps Explained - p. 363 651. Additional Resources - p. 363 652. Question 112 A Classical Mannich Approach to Isoquinoline Alkaloids Leads to an Unexpected Product - p. 363 653. Solution - p. 364 654. Balanced Chemical Equation - p. 364 655. Key Steps Explained - p. 365 656. Additional Resources - p. 365 657. Question 113 Reaction of Benzothiazole With DMAD - p. 365 658. Solution - p. 365 659. Key Steps Explained - p. 366 660. Additional Resources - p. 367 661. Question 114 Inhibition of the l-DOPA to l-Dopaquinone Oxidation - p. 367 662. Solution - p. 367 663. Balanced Chemical Equation - p. 367 664. Key Steps Explained - p. 367 665. Additional Resources - p. 367 666. Question 115 A One-Pot Synthesis of 1,3,6,8-Tetramethyl-2,7-naphthyridine - p. 369 667. Solution: Formation of 1 Part 1 (A to H) - p. 369 668. Solution: Formation of 1 Part 2 (H to 1 Path A) - p. 369 669. Solution: Formation of 1 Part 3 (H to 1 Path B) - p. 370 670. Solution: Formation of 1 Part 4 (ALTERNATE ROUTE: B to O1) - p. 370 671. Solution: Formation of 1 Part 5 (ALTERNATE ROUTE: S to H) - p. 371 672. Solution: Formation of 2 - p. 371 673. Balanced Chemical Equations - p. 371 674. Key Steps Explained - p. 371 675. Question 116 Unexpected Course of a Mannich Reaction in Alkaloid Synthesis - p. 373 676. Solution - p. 374 677. Balanced Chemical Equation - p. 374 678. Key Steps Explained - p. 375 679. Additional Resources - p. 375 680. Question 117 Synthesis of Thioindigo - p. 375 681. Solution - p. 376 682. Balanced Chemical Equation - p. 377 683. Key Steps Explained - p. 377 684. Additional Resources - p. 377 685. Question 118 An Unexpected Reaction During Studies of Amine Oxide Rearrangements - p. 378 686. Solution: 1 to 3 (Expected Product) - p. 378 687. Solution: 1 to 2 (Observed Product) - p. 378 688. Balanced Chemical Equation - p. 378 689. Key Steps Explained - p. 380 690. Additional Resources - p. 380 691. Question 119 An Unusual Phosphite-Induced Deoxygenation of a Nitronaphthalene - p. 380 692. Solution: 1 to 2 Authors’ Mechanism - p. 381 693. Solution: 1 to 2 Alternative Mechanism - p. 382 694. Solution: 3 to 2 Authors’ Mechanism - p. 383 695. Solution: 3 to 2 Alternative Mechanism - p. 383 696. Balanced Chemical Equation - p. 383 697. Key Steps Explained - p. 383 698. Additional Resources - p. 385 699. Question 120 A Benzimidazole to Pyrroloquinoxaline Transformation - p. 385 700. Solution - p. 386 701. Balanced Chemical Equation - p. 386 702. Key Steps Explained - p. 386 703. Additional Resources - p. 387 704. Question 121 Acid-Catalyzed Benzophenone Isomerization - p. 388 705. Solution: Hayashi Mechanism1 - p. 388 706. Solution: Sandin Mechanism2 - p. 389 707. Solution: Wang Mechanism3 - p. 389 708. Key Steps Explained - p. 390 709. Additional Resources - p. 393 710. Question 122 2-Oxabicyclo[1.1.0]butanone Is Not Easily Accessible - p. 393 711. Solution: Authors’ Mechanism - p. 394 712. Solution: Alternative Mechanism - p. 394 713. Balanced Chemical Equation - p. 394 714. Key Steps Explained - p. 394 715. Additional Resources - p. 395 716. Question 123 A Simple Synthesis of the Indole Alkaloid Yuehchukene - p. 395 717. Solution - p. 396 718. Key Steps Explained - p. 396 719. Additional Resources - p. 396 720. Question 124 Isoquinoline Rearrangement - p. 397 721. Solution - p. 397 722. Key Steps Explained - p. 398 723. Additional Resources - p. 398 724. Question 125 Multiple Sigmatropic Rearrangements - p. 398 725. Solution: 1 to 2 in PhCl - p. 399 726. Solution: 1 to 2 and 3 in PhCl and AIBN - p. 399 727. Solution: 1 to 3 in pTsOH - p. 400 728. Key Steps Explained - p. 400 729. Additional Resources - p. 401 730. Question 126 A Vilsmeier-Induced Annulation to Benzene - p. 401 731. Solution - p. 402 732. Balanced Chemical Equation - p. 403 733. Key Steps Explained - p. 403 734. Additional Resources - p. 405 735. Question 127 Isopropylidene to 2-Alkyne Conversion - p. 405 736. Solution: Corey2 Mechanism - p. 405 737. Solution: Zard4 Mechanism - p. 406 738. Balanced Chemical Equations - p. 407 739. Key Steps Explained - p. 408 740. Additional Resources - p. 409 741. Question 128 A Tryptamine to Pentacyclic Indoline Transformation - p. 410 742. Solution: 1 to 2 - p. 411 743. Catalyst Regeneration - p. 411 744. Balanced Chemical Equation: 1 to 2 - p. 411 745. Solution: 1 to 3 - p. 412 746. Balanced Chemical Equation: 1 to 3 - p. 412 747. Key Steps Explained - p. 412 748. Additional Resources - p. 413 749. Question 129 Ring Contractions of a Dibenzothiepinone - p. 413 750. Solution: 1 to 2 - p. 414 751. Solution: 1 to 3 - p. 414 752. Solution: 1 to 4 - p. 414 753. Balanced Chemical Equations - p. 415 754. Key Steps Explained - p. 415 755. Additional Resources - p. 415 756. Question 130 Steroid Fragmentation With DDQ - p. 416 757. Solution: 1 to 2 - p. 417 758. Solution: 1 to 3 - p. 417 759. Solution: 1 to 4 - p. 418 760. Balanced Chemical Equations - p. 418 761. Key Steps Explained - p. 419 762. Additional Resources - p. 420 763. Question 131 A Base-Induced Vinylcyclopropane Rearrangement - p. 421 764. Solution - p. 421 765. Balanced Chemical Equation - p. 421 766. Key Steps Explained - p. 422 767. Additional Resources - p. 422 768. Question 132 4-Demethoxydaunomycin: The Desired Result, but Not According to Plan - p. 424 769. Solution: 1 to 3 - p. 424 770. Solution: 3 to 4 - p. 425 771. Solution: 4 to 5 - p. 425 772. Solution: 5 to 2 - p. 425 773. Key Steps Explained - p. 426 774. Additional Resources - p. 427 775. Question 133 Three Isomeric Hexadienols Give the Same Bicyclic Lactone - p. 428 776. Solution: 1 to 4 - p. 428 777. Solution: 2 to 4 - p. 429 778. Solution: 3 to 4 - p. 429 779. Key Steps Explained - p. 429 780. Additional Resources - p. 430 781. Question 134 Degradation of Antibiotic X-537A - p. 430 782. Solution: 2 to 3 and A - p. 431 783. Solution: A to 5 - p. 431 784. Balanced Chemical Equation: 2 to 3 and 5 - p. 431 785. Solution: 2 to 4 - p. 431 786. Solution: D to 6 - p. 432 787. Balanced Chemical Equation: 2 to 3 and 6 - p. 432 788. Key Steps Explained - p. 432 789. Additional Resources - p. 433 790. Question 135 Steroid Rearrangements: Appearances Can Be Deceptive - p. 433 791. Solution - p. 434 792. Additional Resources - p. 438 793. Question 136 Synthesis of Eburna and Aspidosperma Alkaloids - p. 439 794. Solution: 2 to 3a and 3b - p. 439 795. Balanced Chemical Equation: 2 to 3a and 3b - p. 440 796. Solution: 2 to 4 and 5 - p. 440 797. Balanced Chemical Equations: 2 to 4 and 5 - p. 440 798. Key Steps Explained - p. 441 799. Additional Resources - p. 441 800. Question 137 Synthesis of Highly Hindered Cyclic Amines - p. 441 801. Solution: 1 to 2 - p. 442 802. Solution: 1 to 3 - p. 442 803. Balanced Chemical Equations: 1 to 2 and 3 - p. 442 804. Solution: 4 to 5 and 6 - p. 443 805. Balanced Chemical Equations: 4 to 5 and 6 - p. 443 806. Key Steps Explained - p. 443 807. Additional Resources - p. 444 808. Question 138 A 1,2-Dihydrobenzocyclobutane to Isochroman-3-one Conversion - p. 445 809. Solution - p. 445 810. Key Steps Explained - p. 445 811. Additional Resources - p. 445 812. Question 139 An Unexpectedly Facile Decarboxylation - p. 446 813. Solution - p. 446 814. Balanced Chemical Equation - p. 447 815. Key Steps Explained - p. 447 816. Additional Resources - p. 447 817. Question 140 Regiospecific Synthesis of a 1,2-Dihydronaphthalene - p. 448 818. Solution - p. 448 819. Balanced Chemical Equation - p. 448 820. Key Steps Explained - p. 449 821. Additional Resources - p. 449 822. Question 141 Degradation of Terramycin - p. 449 823. Solution - p. 449 824. Balanced Chemical Equation - p. 451 825. Key Steps Explained - p. 451 826. Additional Resources - p. 451 827. Question 142 Synthesis of Bi-indane-l,3-dione - p. 452 828. Solution: 1 and 2 to 3 - p. 452 829. Solution: 3 to 4 - p. 452 830. Solution: 4 to 5 - p. 453 831. Solution: 5 to 6 - p. 453 832. Key Steps Explained - p. 453 833. Additional Resources - p. 454 834. Question 143 A Coumarin to Cyclopentenone Transformation - p. 454 835. Solution - p. 454 836. Balanced Chemical Equation - p. 454 837. Key Steps Explained - p. 454 838. Additional Resources - p. 456 839. Question 144 “Synthetic Heroin” and Parkinsonism - p. 456 840. Solution - p. 457 841. Balanced Chemical Equation - p. 457 842. Key Steps Explained - p. 457 843. Additional Resources - p. 461 844. Question 145 Rearrangement of 6-Hydroxyprotopine to Dihydrosanguinarine - p. 461 845. Solution - p. 461 846. Key Steps Explained - p. 461 847. Additional Resources - p. 461 848. Question 146 Biotin Synthesis: Sulfur Preempts a Beckmann Rearrangement - p. 461 849. Solution - p. 463 850. Key Steps Explained - p. 463 851. Additional Resources - p. 464 852. Question 147 A 1,4-Dithiin to Thiophene Rearrangement - p. 464 853. Solution: 1 to 2 - p. 465 854. Solution: 1 to 3 - p. 465 855. Balanced Chemical Equation: 1 to 3 - p. 465 856. Key Steps Explained - p. 466 857. Additional Resources - p. 466 858. Question 148 An Intramolecular Wittig Reaction - p. 467 859. Solution: 1 to 2 - p. 467 860. Solution: 1 to 3 - p. 467 861. Key Steps Explained - p. 468 862. Additional Resources - p. 468 863. Question 149 Amination of a Cephalosporin - p. 469 864. Solution: 1 to 2 - p. 469 865. Solution: 2 to 3 - p. 469 866. Key Steps Explained - p. 470 867. Additional Resources - p. 470 868. Question 150 A Uracil to 1,2,3-Triazole Conversion - p. 470 869. Solution: Authors’ Mechanism - p. 471 870. Solution: Alternative Mechanism - p. 472 871. Balanced Chemical Equation - p. 472 872. Key Steps Explained - p. 472 873. Additional Resources - p. 473 874. Chapter 7: Solutions 151 – 200 - p. 473 875. Question 151 Schumm Devinylation of Vinyl Porphyrins - p. 475 876. Solution: Mechanism 1A - p. 477 877. Solution: Mechanism 1B - p. 477 878. Solution: Mechanism 2A - p. 477 879. Solution: Mechanism 2B - p. 478 880. Solution: Mechanism 3 - p. 478 881. Solution: Mechanism 4 - p. 478 882. Key Steps Explained - p. 479 883. Additional Resources - p. 479 884. Question 152 A Uracil to Substituted Benzene Transformation - p. 480 885. Solution: 1 to 2 - p. 480 886. Solution: 1 to 3 - p. 480 887. Key Steps Explained - p. 481 888. Additional Resources - p. 481 889. Question 153 γ-Lactones From Vinyl Sulfoxides - p. 482 890. Solution - p. 482 891. Key Steps Explained - p. 482 892. Additional Resources - p. 483 893. Question 154 Tetrahydrothieno[2,3-c]- and -[3,2-c]pyridine Synthesis - p. 483 894. Solution: 1 to 2 (Weakly Acidic Medium) - p. 484 895. Solution: 1 to 2 and 3 (Strongly Acidic Medium) - p. 484 896. Key Steps Explained - p. 484 897. Additional Resources - p. 484 898. Question 155 Oxothiolan → Oxathian → Oxothiolan → Oxathian - p. 485 899. Solution: 1 to 2 - p. 485 900. Balanced Chemical Equation: 1 to 2 - p. 486 901. Solution: 2 to 3 - p. 486 902. Balanced Chemical Equation: 2 to 3 - p. 486 903. Solution: 3 to 4 - p. 486 904. Balanced Chemical Equation: 3 to 4 - p. 487 905. Key Steps Explained - p. 488 906. Additional Resources - p. 488 907. Question 156 A Thiazolopyrimidine to Pyrrolopyrimidine Transformation - p. 489 908. Solution: 1 and 2 to 3 - p. 489 909. Balanced Chemical Equation: 1 and 2 to 3 - p. 490 910. Solution: 3 to 6 to 5 - p. 490 911. Balanced Chemical Equation: 3 to 6 to 5 - p. 490 912. Solution: 5 to 4 - p. 491 913. Key Steps Explained - p. 491 914. Additional Resources - p. 491 915. Question 157 Oxidation of 1,5-Diacetoxynaphthalene With NBS - p. 492 916. Solution: 1 to 3 to 2 - p. 492 917. Balanced Chemical Equation: 1 to 3 - p. 493 918. Balanced Chemical Equation: 3 to 2 - p. 493 919. Balanced Chemical Equation: 4 to 2 - p. 494 920. Key Steps Explained - p. 494 921. Additional Resources - p. 495 922. Question 158 Badly Chosen Reaction Conditions? - p. 495 923. Solution - p. 496 924. Balanced Chemical Equation - p. 496 925. Key Steps Explained - p. 497 926. Additional Resources - p. 497 927. Question 159 One Step Synthesis of a Highly Symmetrical Hexacyclic System From a Simple Naphthol - p. 497 928. Solution - p. 498 929. Balanced Chemical Equation - p. 498 930. Key Steps Explained - p. 498 931. Additional Resources - p. 499 932. Question 160 A Method for Aryloxylation of p-Cresol - p. 500 933. Solution: 1 to 2 - p. 500 934. Balanced Chemical Equation: 1 to 2 - p. 500 935. Solution: 2 to 3 - p. 501 936. Solution: 2 to 3 Alternative - p. 501 937. Balanced Chemical Equation: 2 to 3 - p. 501 938. Solution: 3 to 4 - p. 502 939. Balanced Chemical Equation: 3 to 4 - p. 502 940. Solution: 3 to 5 - p. 502 941. Balanced Chemical Equation: 3 to 5 - p. 503 942. Key Steps Explained - p. 503 943. Additional Resources - p. 503 944. Question 161 Nitriles From N-Chlorosulfonylamides - p. 504 945. Solution: Nitrile Formation Via Triethylamine - p. 504 946. Solution: Nitrile Formation Via Dimethylformamide (DMF) - p. 504 947. Key Steps Explained - p. 505 948. Additional Resources - p. 505 949. Question 162 Synthesis of Perylenequinone - p. 505 950. Solution - p. 506 951. Balanced Chemical Equation - p. 507 952. Balanced Chemical Redox Equation - p. 507 953. Key Steps Explained - p. 507 954. Additional Resources - p. 508 955. Question 163 A Route to 2-Vinylindoles - p. 509 956. Solution - p. 509 957. Key Steps Explained - p. 510 958. Additional Resources - p. 510 959. Question 164 Brain Cancer: The Mechanism of Action of Temozolomide - p. 510 960. Solution - p. 511 961. Balanced Chemical Equation - p. 511 962. Key Steps Explained - p. 511 963. Additional Resources - p. 511 964. Question 165 Attempted Nef-Type Reaction Leads to 3-Arylpyridine Synthesis - p. 512 965. Solution: Part 1—Reduction - p. 512 966. Solution: Part 2—Rearrangement - p. 512 967. Balanced Chemical Equation - p. 513 968. Key Steps Explained - p. 513 969. Additional Resources - p. 513 970. Question 166 The ArCOMe → ArCCH Transformation - p. 514 971. Solution: 1 to 2 - p. 514 972. Balanced Chemical Equation: 1 to 2 - p. 515 973. Solution: 2 to 3 - p. 515 974. Balanced Chemical Equation: 2 to 3 - p. 515 975. Key Steps Explained - p. 515 976. Additional Resources - p. 515 977. Question 167 β-Amino Nitriles From Azetidones - p. 516 978. Solution - p. 516 979. Key Steps Explained - p. 516 980. Additional Resources - p. 517 981. Question 168 A New Route to 1,3-Disubstituted Naphthalenes - p. 517 982. Solution - p. 518 983. Balanced Chemical Equation - p. 518 984. Key Steps Explained - p. 519 985. Additional Resources - p. 519 986. Question 169 An Efficient Annulation Route to 6-Substituted Indoles - p. 519 987. Solution - p. 520 988. Balanced Chemical Equation - p. 520 989. Key Steps Explained - p. 520 990. Additional Resources - p. 521 991. Question 170 Failure of a Rearrangement: From a Useful Compound to a Useless Product - p. 521 992. Solution - p. 521 993. Key Steps Explained - p. 522 994. Additional Resources - p. 522 995. Question 171 Synthesis of Trisubstituted Isoxazoles - p. 522 996. Solution: 1 to 2 and 2 to 3 - p. 523 997. Balanced Chemical Equation - p. 524 998. Key Steps Explained - p. 524 999. Additional Resources - p. 524 1000. Question 172 2,3-Dihydrobenzofurans From 1,4-Benzoquinones - p. 524 1001. Solution: 1 and 2 to 3 and 3 to 4 - p. 526 1002. Solution: 5 and 6 to 7 - p. 526 1003. Solution: 7 to 8 - p. 526 1004. Balanced Chemical Equation - p. 526 1005. Key Steps Explained - p. 526 1006. Additional Resources - p. 526 1007. Question 173 Easy Construction of a Tricyclic Indole Related to the Mitomycins - p. 528 1008. Solution: 1 to 2 - p. 528 1009. Solution: 2 to 3 - p. 529 1010. Key Steps Explained - p. 529 1011. Additional Resources - p. 529 1012. Question 174 Cycloaddition to a Benzothiopyrylium Salt - p. 529 1013. Solution: 3 to 4 - p. 530 1014. Solution: 3 to 5 - p. 530 1015. Key Steps Explained - p. 531 1016. Additional Resources - p. 531 1017. Question 175 Benzotriazole From 1,2,4-Benzotriazine N-Oxides - p. 531 1018. Solution: 1 to 3 - p. 532 1019. Solution: 2 to 3 - p. 532 1020. Key Steps Explained - p. 532 1021. Additional Resources - p. 533 1022. Question 176 A Furan → Furan Transformation - p. 533 1023. Solution - p. 534 1024. Key Steps Explained - p. 534 1025. Additional Resources - p. 534 1026. Question 177 Ring Expansion of Both Rings of Penicillin Sulfoxides - p. 535 1027. Solution - p. 535 1028. Balanced Chemical Equation - p. 535 1029. Key Steps Explained - p. 535 1030. Additional Resources - p. 538 1031. Question 178 A Retro-Pictet-Spengler Reaction - p. 538 1032. Solution: Epimerization Mechanism 1 (C1N2 Bond Scission) - p. 539 1033. Solution: Epimerization Mechanism 2 (Olefin Protonation) - p. 539 1034. Solution: Epimerization Mechanism 3 (Iminium Ion Formation) - p. 540 1035. Solution: Degradation Mechanism 1 (Retro-Pictet-Spengler) Path A - p. 540 1036. Solution: Degradation Mechanism 1 (Retro-Pictet-Spengler) Path B - p. 540 1037. Key Steps Explained - p. 541 1038. Additional Resources - p. 543 1039. Question 179 An Olefin to α-Hydroxy Ketone Transformation - p. 543 1040. Solution - p. 543 1041. Balanced Chemical Equation - p. 543 1042. Key Steps Explained - p. 543 1043. Additional Resources - p. 543 1044. Question 180 A Benzofuran From a Cyclopropachromone - p. 545 1045. Solution - p. 545 1046. Balanced Chemical Equation - p. 545 1047. Key Steps Explained - p. 546 1048. Additional Resources - p. 546 1049. Question 181 A Pyridocarbazole to Pyridazinocarbazole Rearrangement - p. 546 1050. Solution - p. 547 1051. Balanced Chemical Equation - p. 547 1052. Key Steps Explained - p. 547 1053. Additional Resources - p. 547 1054. Question 182 Substituent Group Effect During Sulfide → Sulfoxide Oxidation - p. 548 1055. Solution - p. 548 1056. Balanced Chemical Equation - p. 548 1057. Key Steps Explained - p. 548 1058. Additional Resources - p. 548 1059. Question 183 Ring Contraction of a Benzodiazepine - p. 550 1060. Solution: Mechanism 1A (Authors’ Mechanism) - p. 550 1061. Solution: Mechanism 1B (Authors’ Mechanism) - p. 550 1062. Solution: Mechanism 2 (Alternative Mechanism) - p. 550 1063. Balanced Chemical Equation - p. 550 1064. Key Steps Explained - p. 550 1065. Additional Resources - p. 553 1066. Question 184 An Indane-1,3-dione Synthesis - p. 553 1067. Solution: Mechanism 1 (Mosher and Meier) - p. 554 1068. Solution: Mechanism 2 (Alternative) - p. 554 1069. Balanced Chemical Equation - p. 554 1070. Key Steps Explained - p. 554 1071. Additional Resources - p. 556 1072. Question 185 An Azepine to Cyclohexadienone Ring Contraction - p. 556 1073. Solution - p. 557 1074. Balanced Chemical Equation - p. 557 1075. Key Steps Explained - p. 557 1076. Additional Resources - p. 559 1077. Question 186 Xanthopterin From Pterin 8-Oxide - p. 559 1078. Solution - p. 559 1079. Balanced Chemical Equation - p. 559 1080. Key Steps Explained - p. 559 1081. Additional Resources - p. 561 1082. Question 187 Fused Dihydro-l,4-dithiins From Chromanones - p. 561 1083. Solution - p. 561 1084. Balanced Chemical Equation - p. 561 1085. Key Steps Explained - p. 561 1086. Additional Resources - p. 563 1087. Question 188 The “Additive Pummerer Reaction” - p. 563 1088. Solution: 1 to 3 - p. 564 1089. Solution: 1 to 4 - p. 564 1090. Key Steps Explained - p. 564 1091. Additional Resources - p. 566 1092. Question 189 An Illustration of the Problem of Artifacts in Natural Product Chemistry - p. 566 1093. Solution - p. 566 1094. Key Steps Explained - p. 566 1095. Additional Resources - p. 568 1096. Question 190 Vinylogy, and a Stereochemical Puzzle - p. 568 1097. Solution: Mechanism 1 (Kiehlmann et al.) - p. 568 1098. Balanced Chemical Equation: Mechanism 1 - p. 569 1099. Solution: Mechanism 2 (Acevado et al.) - p. 569 1100. Balanced Chemical Equation: Mechanism 2 - p. 569 1101. Key Steps Explained - p. 570 1102. Additional Resources - p. 574 1103. Question 191 A Simple, High Yielding Route to a Cage Compound - p. 574 1104. Solution: 1 to 2 - p. 575 1105. Solution: 1 to 3 - p. 575 1106. Key Steps Explained - p. 575 1107. Additional Resources - p. 577 1108. Question 192 Not All Ketals Hydrolyze Easily in the Expected Manner - p. 577 1109. Solution: 1 to 2 - p. 578 1110. Solution: 1 to 2 and 3 - p. 578 1111. Key Steps Explained - p. 579 1112. Additional Resources - p. 579 1113. Question 193 From a Tricycle to a Ring Expanded Bicycle - p. 579 1114. Solution - p. 580 1115. Key Steps Explained - p. 581 1116. Additional Resources - p. 582 1117. Question 194 A Flavone From a Chromanone - p. 582 1118. Solution: 1 to 2 - p. 583 1119. Solution: 2 to 3 (at Elevated Temperature) - p. 583 1120. Solution: 2 to 4 (at Elevated Temperature NO Added Base) - p. 583 1121. Solution: 1 to 4 (With Added Base) - p. 583 1122. Key Steps Explained - p. 584 1123. Additional Resources - p. 585 1124. Question 195 Thiophene Ylide Rearrangement - p. 586 1125. Solution - p. 586 1126. Key Steps Explained - p. 586 1127. Additional Resources - p. 587 1128. Question 196 A Stepwise 2π + 2π Intermolecular Cycloaddition - p. 587 1129. Solution - p. 588 1130. Key Steps Explained - p. 588 1131. Additional Resources - p. 588 1132. Question 197 Rearrangement of an Aryl Propargyl Ether - p. 588 1133. Solution - p. 589 1134. Key Steps Explained - p. 589 1135. Additional Resources - p. 590 1136. Question 198 The Best Laid Plans…… - p. 590 1137. Solution: 1 to 2 (Expected Result) Step 1 - p. 591 1138. Solution: 1 to 2 (Expected Result) Step 2 - p. 591 1139. Solution: 1 to 3 (Observed Result) - p. 591 1140. Alternative Pathway From Intermediate D′ - p. 591 1141. Balanced Chemical Equations - p. 591 1142. Key Steps Explained - p. 593 1143. Additional Resources - p. 593 1144. Question 199 A New Synthesis of Substituted Ninhydrins - p. 595 1145. Solution - p. 595 1146. Balanced Chemical Equation - p. 595 1147. Key Steps Explained - p. 595 1148. Additional Resources - p. 597 1149. Question 200 Thermal Elimination Reactions Often Fail - p. 598 1150. Solution - p. 599 1151. Key Steps Explained - p. 599 1152. Additional Resources - p. 599 1153. Chapter 8: Solutions 201 – 250 - p. 599 1154. Question 201 The Wrong Choice of Reaction Conditions? How Not to Prepare an Acid Chloride - p. 601 1155. Solution - p. 601 1156. Balanced Chemical Equation - p. 602 1157. Key Steps Explained - p. 602 1158. Additional Resources - p. 602 1159. Question 202 Quantitative Yield Isomerization of a Xylenol Derivative… - p. 603 1160. Solution - p. 603 1161. Key Steps Explained - p. 603 1162. Additional Resources - p. 604 1163. Question 203 …and an Alternative Route to the Starting Material for Problem 202 - p. 604 1164. Solution: 1 to 2 - p. 605 1165. Solution: 1 to A - p. 605 1166. Solution: A to 2 - p. 605 1167. Key Steps Explained - p. 606 1168. Additional Resources - p. 606 1169. Question 204 Hydride-Induced Rearrangements With Indole Alkaloid Intermediates - p. 607 1170. Solution - p. 607 1171. Balanced Chemical Equation - p. 608 1172. Work-Up Reaction - p. 608 1173. Key Steps Explained - p. 608 1174. Additional Resources - p. 608 1175. Question 205 An Unusual “Hydrolysis” Product of 2-Nitrosopyridine - p. 609 1176. Solution - p. 609 1177. Balanced Chemical Equation - p. 609 1178. Key Steps Explained - p. 609 1179. Additional Resources - p. 612 1180. Question 206 A Quinolizine to Indolizine Transformation - p. 612 1181. Solution: 1 to A - p. 613 1182. Solution: A to 2 - p. 613 1183. Key Steps Explained - p. 613 1184. Additional Resources - p. 614 1185. Question 207 SNHetAr Reactions Often Proceed With Complications - p. 614 1186. Solution: 1 to 2 (ipso Substitution) - p. 614 1187. Solution: 1 to 3 (tele Substitution) - p. 615 1188. Solution: 1 to 4 (ANRORC Mechanism) - p. 615 1189. Balanced Chemical Equations - p. 615 1190. Key Steps Explained - p. 615 1191. Additional Resources - p. 617 1192. Question 208 Rearrangement During Recrystallization - p. 617 1193. Solution: 1 and 2 to 3 - p. 617 1194. Solution: 3 to 4 - p. 618 1195. Solution: 4 to 5 - p. 618 1196. Balanced Chemical Equation (4 to 5) - p. 619 1197. Key Steps Explained - p. 619 1198. Additional Resources - p. 619 1199. Question 209 Another Attempt to Reduce a Ketone Goes Wrong - p. 620 1200. Solution - p. 620 1201. Balanced Chemical Equation - p. 621 1202. Key Steps Explained - p. 621 1203. Additional Resources - p. 621 1204. Question 210 A More Complex Benzocyclobutane to Isochroman-3-one Rearrangement (c.f. Problem 138) - p. 622 1205. Solution - p. 622 1206. Key Steps Explained - p. 623 1207. Additional Resources - p. 623 1208. Question 211 Indoles by Solvometalation Ring Closure - p. 624 1209. Solution - p. 624 1210. Balanced Chemical Equation - p. 625 1211. Key Steps Explained - p. 625 1212. Additional Resources - p. 625 1213. Question 212 An Unusual—But Inefficient—Synthesis of Methyl 1-Hydroxynaphthalene-2-carboxylate - p. 625 1214. Solution: Mechanism A - p. 626 1215. Solution: Mechanism B - p. 626 1216. Solution: Mechanism C - p. 626 1217. Key Steps Explained - p. 626 1218. Additional Resources - p. 627 1219. Question 213 Synthesis of α-Arylalkanoic Acids From Acetophenones - p. 628 1220. Solution: B to C - p. 629 1221. Solution: C to D - p. 629 1222. Solution: D to 2 - p. 629 1223. Key Steps Explained - p. 629 1224. Additional Resources - p. 630 1225. Question 214 Triazene-Triazole-Triazole Interconversions - p. 630 1226. Solution: 1 to 2 to 3 - p. 631 1227. Key Steps Explained - p. 631 1228. Additional Resources - p. 632 1229. Question 215 Reissert Compounds as Precursors to Novel Phthalides - p. 632 1230. Solution - p. 633 1231. Balanced Chemical Equation - p. 633 1232. Key Steps Explained - p. 633 1233. Additional Resources - p. 633 1234. Question 216 Di-t-butylacetylene Does Not Cycloadd to 2-Pyrone - p. 634 1235. Solution - p. 634 1236. Key Steps Explained - p. 635 1237. Additional Resources - p. 635 1238. Question 217 A Failed Thorpe-Dieckmann Cyclization: “Obvious” Reactions Are Not Always Well Behaved… - p. 635 1239. Solution - p. 636 1240. Balanced Chemical Equation - p. 636 1241. Key Steps Explained - p. 637 1242. Additional Resources - p. 637 1243. Question 218 …and Can Lead to Remarkable Rearrangements: A Failed Thorpe-Ziegler Cyclization - p. 637 1244. Solution - p. 638 1245. Key Steps Explained - p. 638 1246. Additional Resources - p. 638 1247. Question 219 A Remarkably Stable Tertiary Alcohol by Solvolysis of a Primary Tosylate - p. 639 1248. Solution: Mechanism A—Bornyl Path (Helicopter View) - p. 639 1249. Solution: Mechanism B—Fenchyl Path (Helicopter View) - p. 639 1250. Key Steps Explained - p. 641 1251. Additional Resources - p. 643 1252. Question 220 “Anionic Activation” for the Preparation of Fluoroheterocycles - p. 645 1253. Solution: 1 to 2 Via Phenylacetylene - p. 645 1254. Balanced Chemical Equation: 1 to 2 Via Phenylacetylene - p. 646 1255. Solution: 1 to 2 Via Acetophenone - p. 646 1256. Balanced Chemical Equation: 1 to 2 Via Acetophenone - p. 646 1257. Solution: 3 to 4 - p. 646 1258. Balanced Chemical Equation: 3 to 4 - p. 647 1259. Key Steps Explained - p. 647 1260. Additional Resources - p. 647 1261. Question 221 Synthesis of a 5-(2-Quinolyl)pyrimidine - p. 647 1262. Solution: B to C - p. 648 1263. Balanced Chemical Equation: B to C - p. 648 1264. Key Steps Explained - p. 648 1265. Additional Resources - p. 650 1266. Question 222 “Obvious” and “Nonobvious” Pathways to a Highly Substituted Pyridine and Aniline - p. 650 1267. Solution: Formation of 3 - p. 651 1268. Balanced Chemical Equation for Formation of 3 - p. 651 1269. Solution: Formation of 4 Obvious Pathway - p. 651 1270. Balanced Chemical Equation for Formation of 4 Obvious Pathway - p. 652 1271. Solution: Formation of 4 Nonobvious Pathway - p. 652 1272. Balanced Chemical Equation for Formation of 4 Nonobvious Pathway - p. 652 1273. Key Steps Explained - p. 652 1274. Additional Resources - p. 653 1275. Question 223 A 1-Isoquinolone Synthesis - p. 654 1276. Solution - p. 654 1277. Balanced Chemical Equation - p. 655 1278. Key Steps Explained - p. 655 1279. Additional Resources - p. 655 1280. Question 224 Selective Cleavage of the Mycinose Sugar From the Macrolide Antibiotic Tylosin - p. 655 1281. Solution - p. 656 1282. Balanced Chemical Equation - p. 657 1283. Key Steps Explained - p. 657 1284. Additional Resources - p. 657 1285. Question 225 Unexpected Formation of an Enamide - p. 657 1286. Solution - p. 658 1287. Balanced Chemical Equation - p. 658 1288. Key Steps Explained - p. 658 1289. Additional Resources - p. 659 1290. Question 226 Highly Functionalized Furans From 3-Bromochromone - p. 659 1291. Solution - p. 659 1292. Key Steps Explained - p. 660 1293. Additional Resources - p. 660 1294. Question 227 A One-Pot Benzene → Naphthalene Transformation - p. 660 1295. Solution - p. 661 1296. Key Steps Explained - p. 661 1297. Additional Resources - p. 662 1298. Question 228 Vicarious Nucleophilic Substitution Routes From Simple to Complex Phenols - p. 662 1299. Solution: Formation of 1 - p. 663 1300. Solution: Formation of 2 (Mechanism Version 1) - p. 663 1301. Solution: Formation of 3 (Mechanism Version 2) - p. 664 1302. Solution: Formation of 4 (Mechanism Version 3) - p. 664 1303. Key Steps Explained - p. 664 1304. Additional Resources - p. 665 1305. Question 229 Lewis Acid-Catalyzed Rearrangement of Humulene 8,9-Epoxide - p. 666 1306. Solution - p. 666 1307. Key Steps Explained - p. 666 1308. Additional Resources - p. 667 1309. Question 230 From a Dihydrofuran to an Indole-3-acetate - p. 667 1310. Solution: Formation of 1 - p. 668 1311. Solution: Formation of 2 - p. 668 1312. Key Steps Explained - p. 668 1313. Additional Resources - p. 669 1314. Question 231 Reaction of Fervenulin 4-Oxide With DMAD: The Role of Solvent - p. 669 1315. Solution: 1 → 2 - p. 670 1316. Solution: 1 → 3 - p. 670 1317. Solution: 1 → 4 - p. 671 1318. Balanced Chemical Equations - p. 671 1319. Key Steps Explained - p. 671 1320. Additional Resources - p. 672 1321. Question 232 Rearrangement of 4-Quinazolinylhydrazines - p. 672 1322. Solution: Rearrangement Under Neutral pH - p. 673 1323. Solution: Hydrolysis Under Acidic pH - p. 673 1324. Solution: Hydrolysis Under Basic pH - p. 674 1325. Key Steps Explained - p. 674 1326. Additional Resources - p. 676 1327. Question 233 A Failed Approach to the Oxetan-3-one System - p. 678 1328. Balanced Chemical Equations - p. 680 1329. Additional Resources - p. 680 1330. Question 234 Tricyclics From Furfural - p. 681 1331. Solution: Furfural to 2 - p. 681 1332. Solution: 2 to 3 - p. 681 1333. Solution: 3 to 4 - p. 681 1334. Solution: 4 to 5 - p. 681 1335. Solution: 5 to 6 - p. 683 1336. Key Steps Explained - p. 683 1337. Additional Resources - p. 684 1338. Question 235 An Ylide-Based Synthesis of 4-Phenylisocoumarin - p. 684 1339. Solution: 1 → 2 - p. 685 1340. Solution: 2 → 3 - p. 685 1341. Balanced Chemical Equations - p. 686 1342. Key Steps Explained - p. 686 1343. Additional Resources - p. 686 1344. Question 236 Model Studies for Mitomycin A Synthesis Lead to a New Preparation of Pyrroloindoles - p. 686 1345. Solution: 1 → 2 - p. 687 1346. Solution: 1 → 3 - p. 687 1347. Solution: 1 → 4 - p. 688 1348. Key Steps Explained - p. 688 1349. Additional Resources - p. 689 1350. Question 237 Formation of N-Cyanofluoren-9-imine From 9-Dinitromethylenefluorene - p. 689 1351. Solution - p. 689 1352. Balanced Chemical Equation - p. 689 1353. Key Steps Explained - p. 689 1354. Additional Resources - p. 691 1355. Question 238 Methylphenylacetic Acids From Butenolides - p. 691 1356. Solution: 1 → 2 - p. 692 1357. Solution: 3 → 4 - p. 692 1358. Key Steps Explained - p. 692 1359. Additional Resources - p. 693 1360. Question 239 Base-Induced Quinoline Rearrangements - p. 693 1361. Solution - p. 694 1362. Balanced Chemical Equation - p. 694 1363. Key Steps Explained - p. 694 1364. Additional Resources - p. 695 1365. Question 240 The Angucyclines: Rearrangement of Angular to Linear Tetracycles - p. 695 1366. Solution - p. 696 1367. Key Steps Explained - p. 696 1368. Additional Resources - p. 696 1369. Question 241 1,2-Dihydropyridines From 2,3-Dihydro-4-pyridones - p. 697 1370. Solution - p. 697 1371. Key Steps Explained - p. 697 1372. Additional Resources - p. 698 1373. Question 242 The Vitamin K to Vitamin K Oxide Transformation - p. 698 1374. Solution: Mechanism 1 - p. 699 1375. Solution: Mechanism 2 - p. 699 1376. Key Steps Explained - p. 699 1377. Additional Resources - p. 700 1378. Question 243 Rearrangement During Intramolecular Cyclization to the Indole 4-Position - p. 700 1379. Solution - p. 700 1380. Key Steps Explained - p. 700 1381. Additional Resources - p. 702 1382. Question 244 4-Quinolone Antibacterials: A New Synthesis - p. 702 1383. Solution: 1 to 2 - p. 703 1384. Solution: 2 to 3 - p. 703 1385. Solution: 3 to 4 - p. 703 1386. Key Steps Explained - p. 703 1387. Additional Resources - p. 704 1388. Question 245 An Efficient Synthesis of Fused 1,3-Dithiol-2-ones - p. 704 1389. Solution - p. 705 1390. Key Steps Explained - p. 705 1391. Additional Resources - p. 705 1392. Question 246 The “Double Functional Group Transformation”: Terminally Unsaturated Nitriles From 1-Nitrocycloalkenes - p. 706 1393. Solution - p. 706 1394. Balanced Chemical Equation - p. 706 1395. Key Steps Explained - p. 706 1396. Additional Resources - p. 707 1397. Question 247 Lewis Acid-Catalyzed Condensation of Indole With 1,3-Cydohexanedione - p. 708 1398. Solution: Formation of 1 - p. 708 1399. Solution: Formation of 2 - p. 709 1400. Key Steps Explained - p. 709 1401. Additional Resources - p. 710 1402. Question 248 Serendipitous Preparation of a Pyrrole Precursor to Porphyrins - p. 710 1403. Solution - p. 711 1404. Balanced Chemical Equation - p. 711 1405. Key Steps Explained - p. 711 1406. Additional Resources - p. 713 1407. Question 249 A Chromone Ring Contraction - p. 714 1408. Solution - p. 714 1409. Balanced Chemical Equation - p. 714 1410. Key Steps Explained - p. 714 1411. Additional Resources - p. 716 1412. Question 250 A Simple Conversion of Hydroquinone to a Benzofuran, but Which Mechanism? - p. 716 1413. Solution: Mechanism 1 (C-Alkylation-Lactonization) - p. 717 1414. Solution: Mechanism 2 (O-Alkylation-Michael-Lactonization) - p. 717 1415. Balanced Chemical Equation - p. 718 1416. Key Steps Explained - p. 718 1417. Additional Resources - p. 719 1418. Chapter 9: Solutions 251 – 300 - p. 719 1419. Question 251 A Remarkable Loss of One Carbon Atom in the Indole Alkaloid Field - p. 721 1420. Solution - p. 721 1421. Solution—Possibility 1 (With Intervention of Retro-Mannich Process) - p. 722 1422. Solution—Possibility 2 (Without Intervention of Retro-Mannich Process) - p. 722 1423. Balanced Chemical Equation - p. 723 1424. Key Steps Explained - p. 723 1425. Additional Resources - p. 723 1426. Question 252 A “Nonobvious” Cycloaddition Reaction - p. 724 1427. Solution - p. 724 1428. Balanced Chemical Equation - p. 724 1429. Key Steps Explained - p. 725 1430. Additional Resources - p. 725 1431. Question 253 More Radical Cascades and a Formal [2 + 2 + 2] Cycloaddition of a Dienyne - p. 726 1432. Solution - p. 726 1433. Key Steps Explained - p. 727 1434. Additional Resources - p. 728 1435. Question 254 LTA-Induced Acetoxylation and Rearrangement of a Phenol - p. 728 1436. Key Steps Explained - p. 728 1437. Solution - p. 729 1438. Balanced Chemical Equation - p. 729 1439. Mechanism for 3 - p. 730 1440. Additional Resources - p. 730 1441. Question 255 How Cocaine Decomposes at 550°C - p. 730 1442. Solution - p. 731 1443. Key Steps Explained - p. 731 1444. Additional Resources - p. 731 1445. Question 256 A Highly Efficient Anilide to Benzimidazole Transformation - p. 732 1446. Solution - p. 732 1447. Balanced Chemical Equation - p. 733 1448. Key Steps Explained - p. 733 1449. Additional Resources - p. 734 1450. Question 257 The Baeyer-Drewson Synthesis of Indigo - p. 734 1451. Solution - p. 734 1452. Balanced Chemical Equation - p. 736 1453. Key Steps Explained - p. 736 1454. Additional Resources - p. 736 1455. Question 258 The Marschalk Reaction - p. 737 1456. Solution - p. 737 1457. Balanced Chemical Equation - p. 738 1458. Key Steps Explained - p. 738 1459. Additional Resources - p. 738 1460. Question 259 A 1,3-Cyclohexanedione to 2-Cyclohexenone Conversion - p. 739 1461. Solution - p. 739 1462. Balanced Chemical Equation - p. 740 1463. Key Steps Explained - p. 740 1464. Additional Resources - p. 740 1465. Question 260 Reaction of a Steroidal Olefin With Br2/AgOAc - p. 741 1466. Key Steps Explained - p. 741 1467. Solution - p. 742 1468. Balanced Chemical Equation - p. 742 1469. Additional Resources - p. 743 1470. Question 261 A Most Unusual Synthesis of Tropones From Phenols - p. 743 1471. Solution: 1 to 2 - p. 744 1472. Solution: 3 to G - p. 744 1473. Solution: G to 4 - p. 745 1474. Balanced Chemical Equation: G to 4 - p. 745 1475. Key Steps Explained - p. 745 1476. Additional Resources - p. 747 1477. Question 262 Side-Chain Manipulation With a Purine Derivative: Unexpected Formation of a Thietane - p. 747 1478. Solution - p. 748 1479. Key Steps Explained - p. 748 1480. Additional Resources - p. 748 1481. Question 263 An Isoxazoline to Pyridine N-Oxide Transformation - p. 749 1482. Solution - p. 749 1483. Key Steps Explained - p. 749 1484. Additional Resources - p. 750 1485. Question 264 A Simple Synthesis of the Lignan Carpanone - p. 750 1486. Solution - p. 750 1487. Key Steps Explained - p. 751 1488. Additional Resources - p. 751 1489. Question 265 Cyclopentaquinolines by Tandem Reactions - p. 751 1490. Solution - p. 752 1491. Experimental Results and Verification - p. 755 1492. Additional Resources - p. 757 1493. Question 266 Epimerization of Herqueinone - p. 758 1494. Solution: Brooks Mechanism - p. 758 1495. Solution: Proposed Mechanism - p. 759 1496. Key Steps Explained - p. 759 1497. Additional Resources - p. 760 1498. Question 267 A New Method for Amide Bond Formation - p. 760 1499. Solution - p. 761 1500. Key Steps Explained - p. 761 1501. Additional Resources - p. 762 1502. Question 268 A Benzothiazole From Oxidation of Mammalian Red Hair With Hydrogen Peroxide - p. 762 1503. Solution - p. 763 1504. Balanced Chemical Equation - p. 764 1505. Key Steps Explained - p. 764 1506. Additional Resources - p. 764 1507. Question 269 Cyclopentenones From 1,3-Cyclopentanediones - p. 765 1508. Solution: 1 → 2 - p. 765 1509. Solution: C → 3 - p. 766 1510. Key Steps Explained - p. 766 1511. Additional Resources - p. 767 1512. Question 270 A New Synthesis of 1- and 2-Chloronaphthalenes by an Annulation Process - p. 768 1513. Solution: 1 → 2 - p. 769 1514. Solution: 3 → 4 - p. 769 1515. Key Steps Explained - p. 769 1516. Additional Resources - p. 770 1517. Question 271 From the Diterpene Carnosol to the Benzodiazepine Agonist Miltirone - p. 770 1518. Solution: 1 → A - p. 771 1519. Solution: A → 2a - p. 771 1520. Solution: A → 2b - p. 771 1521. Balanced Chemical Equation: 1 → 2a - p. 772 1522. Solution: 2b → 3 - p. 772 1523. Solution: 3 → 4 - p. 773 1524. Balanced Chemical Equation: 1 → 2b - p. 774 1525. Balanced Chemical Equation: 2b → 3 - p. 774 1526. Balanced Chemical Equation: 3 → 4 - p. 774 1527. Key Steps Explained - p. 774 1528. Additional Resources - p. 775 1529. Question 272 Synthesis of Chiral Phthalimidine Derivatives - p. 775 1530. Solution: Synthesis of 1 - p. 776 1531. Solution: Synthesis of 1: Pathway A - p. 776 1532. Solution: Synthesis of 1: Pathway B - p. 777 1533. Solution: Synthesis of 2 - p. 777 1534. Balanced Chemical Equation for the Synthesis of 1 - p. 777 1535. Key Steps Explained - p. 778 1536. Additional Resources - p. 778 1537. Question 273 Remarkable Rearrangement of a Camphor Derivative - p. 780 1538. Solution - p. 780 1539. Balanced Chemical Equation - p. 781 1540. Key Steps Explained - p. 781 1541. Additional Resources - p. 784 1542. Question 274 A Failed Attempt to Prepare Benzylidenethiophthalide by the “Obvious” Method - p. 784 1543. Solution - p. 785 1544. Balanced Chemical Equation - p. 785 1545. Key Steps Explained - p. 786 1546. Additional Resources - p. 786 1547. Question 275 Base-Catalyzed Reactions of Highly Hindered Phenols Used as Antioxidants - p. 786 1548. Solution - p. 786 1549. Balanced Chemical Equation - p. 788 1550. Key Steps Explained - p. 788 1551. Additional Resources - p. 788 1552. Question 276 Oxidative Rearrangement of an Aconitine Derivative - p. 789 1553. Solution: 1 to 2 - p. 789 1554. Balanced Redox Chemical Equation for 1 to 2 - p. 790 1555. Solution: 2 to 3 - p. 790 1556. Balanced Chemical Equation for 2 to 3 - p. 790 1557. Key Steps Explained - p. 790 1558. Balanced Chemical Equation for Hydroxydiphenylacetaldehyde to Benzophenone Transformation - p. 793 1559. Additional Resources - p. 793 1560. Question 277 Decomposition of Akuammicine - p. 793 1561. Solution: Decomposition at 100°C - p. 794 1562. Solution: Decomposition at 140°C - p. 795 1563. Balanced Chemical Equation: Decomposition at 100°C - p. 795 1564. Balanced Chemical Equation: Decomposition at 140°C - p. 795 1565. Key Steps Explained - p. 795 1566. Additional Resources - p. 796 1567. Question 278 Extending the Favorskii Reaction - p. 796 1568. Solution: 1 → 2 - p. 797 1569. Solution: 1 → 3 - p. 797 1570. Solution: 1 → 4 - p. 797 1571. Balanced Chemical Equation: 1 → 2 - p. 798 1572. Balanced Chemical Equation: 1 → 3 - p. 798 1573. Balanced Chemical Equation: 1 → 4 - p. 798 1574. Key Steps Explained - p. 798 1575. Additional Resources - p. 799 1576. Question 279 Dihydroxylation/Base Treatment of the Westphalen Ketone - p. 799 1577. Solution: 1 → A - p. 800 1578. Balanced Chemical Equation: 1 → A - p. 800 1579. Solution: A → 2 - p. 800 1580. Solution: B → 3 - p. 801 1581. Balanced Chemical Equation: A → 2 - p. 801 1582. Balanced Chemical Equation: 2 → 3 - p. 802 1583. Key Steps Explained - p. 802 1584. Additional Resources - p. 802 1585. Question 280 Quantitative Conversion of a Vinylogous Thioamide Into a Thiophene - p. 802 1586. Solution: Possibility 1: Sulfonium Ion Intermediate - p. 803 1587. Solution: Possibility 2: Iminium Ion Intermediate - p. 803 1588. Solution: Possibility 3 - p. 804 1589. Key Steps Explained - p. 804 1590. Additional Resources - p. 804 1591. Question 281 Rearrangements During Synthetic Studies on Carba-Sugars - p. 805 1592. Solution: (i) 2 → 3 With Triflic Anhydride - p. 805 1593. Solution: (ii) Dihydroxylation Mechanism - p. 805 1594. Balanced Chemical Equation: Dihydroxylation of 4 - p. 805 1595. Solution: (ii) Formation of 6 - p. 805 1596. Solution: (ii) Formation of 5 - p. 807 1597. Key Steps Explained - p. 807 1598. Additional Resources - p. 808 1599. Question 282 A Pyrimidine to Pyrazole Transformation - p. 808 1600. Solution - p. 808 1601. Balanced Chemical Equation - p. 809 1602. Key Steps Explained - p. 809 1603. Additional Resources - p. 809 1604. Question 283 Attempted Diastereocontrol in Synthesis of a Homoallylic Alcohol - p. 810 1605. Solution - p. 810 1606. Key Steps Explained - p. 811 1607. Additional Resources - p. 811 1608. Question 284 Arsonium Ylides for Cyclopropane Synthesis - p. 811 1609. Solution - p. 812 1610. Alternate Possible Pathway - p. 812 1611. Key Steps Explained - p. 812 1612. Additional Resources - p. 812 1613. Question 285 Pyridoacridines From 4-Quinolones - p. 813 1614. Solution: 1 to 2 - p. 814 1615. Balanced Chemical Equation: 1 → 2 - p. 815 1616. Solution: F to 3 - p. 815 1617. Balanced Chemical Equation: 1 → 3 - p. 816 1618. Solution: CAN Oxidation of 2 → 4 - p. 816 1619. Balanced Chemical Equation: 2 → 4 - p. 817 1620. Solution: CAN Oxidation of 3 → 4 - p. 817 1621. Balanced Chemical Equation: 3 → 4 - p. 818 1622. Additional Resources - p. 818 1623. Question 286 Imidoyl Radicals in a New Quinoline Synthesis - p. 818 1624. Solution—1 to B - p. 819 1625. Solution—B to 2 - p. 819 1626. Solution—B to 3 - p. 820 1627. Key Steps Explained - p. 820 1628. Additional Resources - p. 820 1629. Question 287 Electrolytic Fluorinative Ring Expansion Reactions - p. 821 1630. Solution - p. 821 1631. Key Steps Explained - p. 821 1632. Additional Resources - p. 822 1633. Question 288 An Isoxazole to 1,3-Oxazine Transformation - p. 822 1634. Key Steps Explained - p. 822 1635. Solution: 3-Phenyl-5-isoxazolone → 1 - p. 823 1636. Solution: 1 → 2 - p. 823 1637. Additional Resources - p. 824 1638. Question 289 Synthesis of Folate Antimetabolites: A Furan to Pyrrole Transformation - p. 824 1639. Solution: Mechanism A - p. 825 1640. Solution: Mechanism B - p. 826 1641. Balanced Chemical Equation (Applies to Both Mechanism A and B) - p. 827 1642. Key Steps Explained - p. 827 1643. Additional Resources - p. 828 1644. Question 290 Rearrangement of a Silylacetylenic Ketone - p. 828 1645. Solution - p. 829 1646. Key Steps Explained - p. 829 1647. Additional Resources - p. 829 1648. Question 291 And More Silyl Rearrangements: A Brook-Retro-Brook Sequence - p. 830 1649. Solution - p. 831 1650. Balanced Chemical Equation - p. 831 1651. Key Steps Explained - p. 831 1652. Additional Resources - p. 832 1653. Question 292 Two Syntheses of Dehydrorotenone - p. 832 1654. Solution: (i) From 21 - p. 833 1655. Balanced Chemical Equation for (i) - p. 833 1656. Solution: (ii) From 3 and 42 Mechanism A - p. 835 1657. Balanced Chemical Equation for Mechanism A - p. 835 1658. Solution: (ii) From 3 and 42 Mechanism B - p. 837 1659. Balanced Chemical Equation for Mechanism B - p. 838 1660. Key Steps Explained - p. 839 1661. Additional Resources - p. 839 1662. Question 293 Radical-Induced Decarboxylation of a Lactone - p. 839 1663. Solution: Pathway A - p. 840 1664. Pathway B - p. 840 1665. Key Steps Explained - p. 841 1666. Additional Resources - p. 841 1667. Question 294 Aryl Azide Thermolysis: “A Series of Rather Involved Rearrangement Reactions” - p. 841 1668. Solution - p. 842 1669. Balanced Chemical Equation - p. 843 1670. Key Steps Explained - p. 843 1671. Balanced Chemical Equation - p. 844 1672. Question 295 An Efficient Route to Hexakis(trifluoromethyl)cyclopentadiene - p. 846 1673. Solution - p. 846 1674. Balanced Chemical Equation - p. 846 1675. Key Steps Explained - p. 847 1676. Additional Resources - p. 847 1677. Question 296 Exploitation of the Boulton-Katritzky Rearrangement: Synthesis of 4,4′-Diamino-3,3′-bifurazan - p. 847 1678. Solution - p. 847 1679. Additional Resources - p. 853 1680. Question 297 Rearrangement During Hydrolysis of a Cyclohexadienone - p. 854 1681. Solution: 1 → 2 - p. 855 1682. Balanced Chemical Equation: 1 → 2 - p. 855 1683. Solution: 2 → 3, 4 - p. 855 1684. Balanced Chemical Equation: 1 → 3, 4 - p. 856 1685. Key Steps Explained - p. 856 1686. Additional Resources - p. 856 1687. Question 298 Less Common Sigmatropic Rearrangements: [3,4], [3,5], or Even [2,3]? - p. 857 1688. Solution: Thionation Mechanism - p. 857 1689. Solution: A → 2 - p. 858 1690. Balanced Chemical Equation: 1 → 2 - p. 858 1691. Solution: B → 3 - p. 858 1692. Balanced Chemical Equation: 1 → 3 - p. 859 1693. Key Steps Explained - p. 859 1694. Additional Resources - p. 859 1695. Question 299 Failure to Construct an Oxetane by SN’ Rearrangement - p. 859 1696. Solution - p. 860 1697. Balanced Chemical Equation - p. 860 1698. Key Steps Explained - p. 860 1699. Additional Resources - p. 861 1700. Question 300 Acid-Catalyzed Isomerization of a Tetraspiroketone - p. 861 1701. Solution: 1 → 2 - p. 862 1702. Solution: 1 → 3 - p. 862 1703. Key Steps Explained - p. 863 1704. Additional Resources - p. 863 1705. Index - p. 865