Asymmetric Epoxidation Catalyzed by r,r-Dimethylmorpholinone Ketone. Methyl Group Effect on Spiro and Planar Transition States

摘要

Asymmetric epoxidation of olefins by using an,Rdimethylmorpholinone-containing chiral ketone catalyst (4) has been investigated. This ketone, which has the combined features of several previously studied catalysts, is an effective catalyst for trans- and trisubstituted olefins, and up to 97% ee has been achieved. The R,R-dimethyl group has significant impact on spiro and planar transition states.