Quinolizidines. XVII. A new access to 9,10-dimethoxy- and 8-hydroxy-9,10-dimethoxybenzo(a)quinolizidine-type Alangium alkaloids from 3-acetylpyridine.
作者:TOZO FUJII、MASASHI OHBA、SHIGEAKI AKIYAMA
DOI:10.1248/cpb.33.5316
日期:——
New syntheses of the ipecac and Alangium alkaloids possessing the 9, 10-dimethoxy- and 8-hydroxy-9, 10-dimethoxybenzo [a] quinolizidine skeletons (types 1 and 2) have now become possible through generally applicable routes starting from 3-acetylpyridine (5). The routes involve the mercuric acetate-edetic acid oxidation of the 3-acetylpiperidine derivatives 9a, b or the alkaline ferricyanide oxidation of the quaternary salts (26a, b and 27a, b) of 3-acetylpyridine equivalents, Wolff-Kishner reduction of the acetyl group or reductive desulfurization of the thioketal group, sulfenylation-dehydrosulfenylation of the lactams 12a, b, Michael reaction of the α, β-unsaturated lactams 15a, b, and de-ethoxycarbonylation of the Michael adducts 16a, b as the main operations.
拥有 9,10-二甲氧基和 8-羟基-9,10-二甲氧基苯并[a]喹嗪骨架(类型 1 和 2)的依培康和阿兰生物碱的新合成方法,现在已经可以通过从 3-乙酰基吡啶 (5) 开始的普遍适用的路线来实现。这些方法包括 3-乙酰基哌啶衍生物 9a 和 b 的醋酸乙酸汞氧化法,或 3-乙酰基吡啶等价物的季盐(26a、b 和 27a、b)的碱性铁氰化物氧化法、乙酰基的沃尔夫-基什纳还原或硫酮基的还原脱硫,内酰胺 12a, b 的亚磺酰化-脱氢亚磺酰化,α, β-不饱和内酰胺 15a, b 的迈克尔反应,迈克尔加合物 16a, b 的脱乙氧基羰基化是主要操作。