Cyclopropane esters holding two quaternary centres were prepared in high yields, complete diastereoselection and up to 83% ee. The reaction described herein entailed reacting (Z)-3-substituted-2-(4-pyridyl)-acrylonitrile, a reactive class of Michael acceptor, with 2-bromomalonate esters in the presence of Cinchona derived phase-transfer catalysts. The reaction allowed multi-gram preparation of the
具有高收率,完全非对映选择性和高达83%ee的制备具有两个季中心的
环丙烷酯。将反应在此描述entailed(反应Ž)-3-取代-2-(4-
吡啶基) -
丙烯腈,反应性类迈克尔受体的,与在存在2-
溴代丙二酯
金鸡纳衍生的相转移催化剂。该反应允许所需产物的多克制备。