Diastereoselective Synthesis of Cephalotaxus Esters via Asymmetric Mukaiyama Aldol Reaction
作者:Guo-Zhen Ma、Peng-Fei Li、Lu Liu、Wei-Dong Z. Li、Li Chen
DOI:10.1021/acs.orglett.7b00743
日期:2017.5.5
carbon stereocenter of the side chain of cephalotaxus esters by means of highly diastereoselective Mukaiyama aldol reactions between α-keto esters (2) and a (Z)-α-chloro ketene silyl acetal. This protocol permitted synthesis of cephalotaxus esters including six natural products in good to excellent yields (up to 94%) with high diastereoselectivities (dr up to 97:3) and could be performed on a multigram
我们报告了协议的高效立体选择性安装头孢酯侧链的手性含氧四取代叔碳立体中心通过α-酮酸酯(2)和(Z)-α-氯之间的高度非对映选择性的Mukaiyama羟醛反应乙烯酮甲硅烷基缩醛。该方案允许合成头孢菌素酯,包括具有高非对映选择性(dr高达97:3)的高至极佳产率(高达94%)的六种天然产物,并且可以以多克规模进行。