A unified asymmetric approach to substituted hexahydroazepine and 7-azabicyclo[2.2.1]heptane ring systems from D(−)-quinic acid: Application to the formal synthesis of (−)-balanol and (−)-epibatidine
作者:Enrichetta Albertini、Achille Barco、Simonetta Benetti、Carmela De Risi、Gian P Pollini、Vinicio Zanirato
DOI:10.1016/s0040-4020(97)10139-9
日期:1997.12
(1R,4S)-N-tert-butoxycarbonyl-7-azabicyclo[2.2.1]heptan-2-one 43, advanced intermediates already taken to (-)-balanol and (-)-epibatidine respectively. While the nitrogen atom ring-insertion via Beckmann rearrangement was the key step for the construction of the hexahydroazepine ring of 17, a regio- and stereospecific intramolecular nucleophilic ring opening of an intermediate cyclic sulfate featured
3,4- O-异亚丙基-3(R),4(S)-二羟基环己酮7是一种由D(-)-奎尼酸1通过五步序列容易制备的Chiron ,已被有效地用作起始原料。 (3的对映选择性合成- [R,4小号- )ñ - p甲苯磺酰-3,4-环氧六氢氮杂 17和(1 - [R,4小号) - ñ -叔丁氧羰基-7-氮杂双环[2.2.1]庚-2-一43,已经分别用于(-)-balanol和(-)-epibatidine的高级中间体。虽然通过贝克曼重排插入氮原子环是构建17的六氢氮杂ring环的关键步骤,但中间环硫酸盐的区域和立体特异性分子内亲核开环是取代7-氮杂双环的方法[2.2。]。 1]庚烷核,为43个。