Optically active (R)-cyanohydrins have been transformed into cyanohydrin esters of opposite configuration under Mitsunobu conditions and subsequently solvolyzed to (S)-cyanohydrins in high chemical and optical yield. The method works well for allylic and benzylic cyanohydrins. Cyanohydrins containing strongly electron donating substituents gave extensive racemization. Saturated aliphatic cyanohydrins
在Mitsunobu条件下,将光学活性的(R)-
氰醇转化为相反构型的
氰醇酯,随后以高
化学和光学收率将其溶剂化为(S)-
氰醇。该方法适用于烯丙基和苄基
氰醇。含有强电子给体取代基的
氰醇化合物具有广泛的消旋作用。饱和脂族
氰醇提供了保留原始构型的酯。根据Mitsunobu反应的机理讨论了这些结果。