Stereodivergent Approach to the Asymmetric Synthesis of Bacillariolides: A Formal Synthesis of <i>e</i><i>nt</i>-Bacillariolide II
作者:Subrata Ghosh、Saikat Sinha、Michael G. B. Drew
DOI:10.1021/ol061377y
日期:2006.8.1
[reaction: see text] Asymmetric synthesis of densely functionalized bicyclic frameworks for entry into bacillariolides I/III and ent-bacillariolide II is reported. The key features are ring-closing metathesis of a pair of diastereomerically related dienes obtained through a stereodivergent route from a R-(+)-glyceraldehyde derivative, transformation of a nonstereoselective cyclopentene ester enolate
[反应:见正文]据报道,致密的功能化双环骨架不对称合成,可进入杆菌内酯I / III和肠杆菌内酯II。关键特征是通过立体发散途径从R-(+)-甘油醛衍生物获得的一对非对映异构相关二烯的闭环易位,通过庞大的烷基化将非立体选择性的环戊烯酯烯酸酯烷基化过程转变为完全立体选择性的二烯酯烯酸酯与大体积的亲电试剂,以及偏远的甲硅烷基氧甲基基团指导环氧化。