Asymmetric Synthesis of AntimalarialAlkaloids (+)-Febrifugine and (+)-Isofebrifugine
作者:Pei-Qiang Huang、Bang-Guo Wei、Yuan-Ping Ruan
DOI:10.1055/s-2003-40988
日期:——
Diastereoselective α-amidoalkylation of N,O-acetal,derivated from controlled regio and diastereoselective reductionof (S)-N-(4-methoxybenzyl)-3-silyloxyglutarimideprovided two diastereomeric 6-allyl-5-silyloxy-2-piperidinonesin 76:24 selectivity. The transformation of the major diastereomerinto a known advanced intermediate allowed the synthesis of (+)-febrifugineand (+)-isofebrifugine.
通过对(S)-N-(4-甲氧基苄基)-3-硅氧基戊二酰亚胺进行受控的区域和非对映选择性还原,进而得到N,O-缩醛衍生物的非对映选择性α-氨基烷基化反应,在76:24的选择性下提供了两种非对映异构的6-烯丙基-5-硅氧基-2-哌啶酮。将主要的非对映异构体转化为已知的高级中间体,实现了(+)-乙胺嘧啶和(+)-异乙胺嘧啶的合成。