The Enantioselective Birch−Cope Sequence for the Synthesis of Carbocyclic Quaternary Stereocenters. Application to the Synthesis of (+)-Mesembrine
作者:Tapas Paul、William P. Malachowski、Jisun Lee
DOI:10.1021/ol0615228
日期:2006.8.1
A synthetic technique for generating carbocyclic quaternary stereocenters with exceptionally high levels of enantioselectivity is described. A sequence of three reactions, enantioselective Birch reduction-allylation, enol ether hydrolysis, and Cope rearrangement, is used to stereoselectively generate chiral quaternary centers on a 2-cyclohexen-1-one ring. The products of the sequence are 4,4-disub
描述了一种用于产生具有极高对映选择性的碳环四元立体中心的合成技术。对映选择性桦木还原-烯丙基化,烯醇醚水解和Cope重排这三个反应的序列用于在2-环己烯-1-酮环上立体选择性地生成手性季中心。该序列的产物是4,4-二取代的-2-羧酰胺-2-环己烯-1-酮结构,是复杂的天然产物合成中的通用中间体。该序列在(+)-半膜合成中的应用说明了这些中间体的实用性。