A stereoselective synthesis of corynantheine-type alkaloids via enamine annulation. Total synthesis of (±)-dihydrocorynantheol and formal total synthesis of (±)-corynantheine and (±)-ajmalicine
作者:Tetsuji Kametani、Naoaki Kanaya、Hiroaki Hino、Shyh-Pyng Huang、Masataka Ihara
DOI:10.1039/p19810003168
日期:——
Enamine annulation between 3,4-dihydro-1-methyl-β-carboline (4) and dimethyl 3-methoxyallylidenemalonate (5) yielded 2-(2,2-dimethoxyethyl)-2,3,4,6,7,12-hexahydro-3-methoxycarbonyl-4-oxoindolo [2,3-a]quinolizine (6), which was transformed into (±)-dihydrocorynantheol (1). (±)-Corynantheal (19), which is convertible into (±)-corynantheine (2) and (±)-ajmalicine (3), was stereoselectively synthesised
3,4-二氢-1-甲基-β-咔啉(4)和3-甲氧基烯丙基丙二酸二甲酯(5)之间的烯胺环化产生2-(2,2-二甲氧基乙基)-2,3,4,6,7,12-六氢-3-甲氧基羰基-4-氧代吲哚[2,3- a ]喹啉(6),其被转化为(±)-二氢七氢萘酚(1)。使用Adams催化剂通过角化反应由(6)立体选择性地合成了可转化为(±)-corynantheine(2)和(±)-ajmalicine(3)的(±)-Corynantheal(19)。