手性螺-环丙烷双内酯化合物的合成与结构

本文进一步研究了5-(l-孟氧基)-3-溴-2(5H)-呋喃酮(1)与氧的亲核试剂,如二苯甲醇、苯甲醇、α-甲基苯甲醇、薄荷醇、冰片醇发生新颖的串联不对称双Michael加成/分子内亲核取代反应,合成了一般方法难以合成的含有多个手性中心的螺[1-溴-4-l-孟氧基-5-氧杂-6-氧代双环[3.1.0]己烷-2,3'-(4'-亲核基-5'-孟氧基丁内酯)](4a-4e)。通过元素分析,IR,UV,^1HNMR,^1^3CNMR,MS,[α]~D^2^0波谱分析数据以及X四圆衍射确定了4a-4e的化学结构和绝对构型。

Synthesis and structure of the chiral spiro-cyclopropane derivatives

Tandem asymmetric reactions of 1 with nucleophilic alcohols afforded optically pure spiro-cyclopropane derivatives with four stereogenic centers 4a ~ 4e in 64% ~ 88% yields with d. e. >98%. The optically pure compounds 4a ~ 4e were identified on the basis of their analytical data, such as [a]D20, UV, IR, 1H NMR, 13C NMR, MS and elemental analysis. The absolute configuration of the chiral spiro-cyclopropane compound (4a) was established by X-ray crystallography.