A simplified procedure for the stereospecific transformation of 1,2-diols into epoxides
作者:Hartmuth C. Kolb、K.Barry Sharpless
DOI:10.1016/s0040-4020(01)88349-6
日期:1992.11
of vicinal diols into epoxides via halohydrin ester intermediates has been developed. This method tolerates a wide range of functionality including acid sensitive functional groups. The transformation proceeds via a, usually highly regioselective, nucleophilic opening of a cyclic acetoxonium intermediate, generated from a cyclic orthoacetate and Me3SiCl, acetyl bromide or acetyl chloride/NaI to form
已经开发出一种简单的“一锅法”程序,用于通过卤代醇酯中间体将邻位二醇转化为环氧化物。该方法可耐受包括酸敏感性官能团在内的多种官能团。变换进行经由环状acetoxonium中间的一个,通常是高度选择性,亲核开口,由环状原乙酸酯和Me产生3用SiCl,乙酰溴或乙酰氯/ NaI分别形成1-乙酰氧基-2-氯化物,1-乙酰氧基-2-溴化物或1-乙酰氧基-2-碘化物中间体。即使有苄基底物也不会发生差向异构。随后的碱介导的甲醇分解以优异的总收率提供了环氧化物。从3- [2-(8-苯基辛基)苯基]丙酸甲酯的高度对映选择性顺式-二羟基化开始,该方法的应用导致白三烯拮抗剂SKF 104353的有效形式合成。