作者:Richard E. Taylor、F. Conrad Engelhardt、Michael J. Schmitt、Haiqing Yuan
DOI:10.1021/ja0037163
日期:2001.4.1
been rationalized by transition-state models in which the important determinants include (i) a minimization of the steric interactions about the forming cyclopropane bond and (ii) an inversion of stereochemistry at the activated homoallylic alcohol position. The cyclopropane product chirality is ultimately controlled by the choice of homoallylic alcohol starting material. Through this method nonracemic
已经开发了将高烯丙基醇立体选择性转化为非对映异构纯顺式、反式 1,2-二取代和 1,2,3-三取代环丙烷的实用且有效的路线。烯烃复分解策略和通过 β-硅效应稳定中间体环丙基羰基阳离子突出了这些路线。关键环化步骤的立体特异性已通过过渡态模型合理化,其中重要的决定因素包括(i)关于形成环丙烷键的空间相互作用的最小化和(ii)在活化的高烯丙醇位置立体化学的反转。环丙烷产品的手性最终由高烯丙醇原料的选择控制。通过这种方法非外消旋,非对映纯的高烯丙醇可以通过两步转化为非外消旋的、非对映纯的环丙烷结构单元。这种通用方法的范围和局限性...