Enantioselective Synthesis of 2‐Aryl Cyclopentanones by Asymmetric Epoxidation and Epoxide Rearrangement

Abstract

Optically active epoxides are prepared by the highly enantioselective epoxidation of benzylidenecyclobutanes using a glucose-derived ketone as the catalyst and oxone as the oxidant. A subsequent Lewis acid catalyzed rearrangement of the resulting epoxides with Et2AlCl or LiI provides α-aryl substituted cyclopentanones in high enantiomeric excess (see scheme; Tol= tolyl).