Chemistry of Oxaziridines. 4. Asymmetric Epoxidation of Unfunctionalized Alkenes Using Chiral 2-Sulfonyloxaziridines: Evidence for a Planar Transition State Geometry

Abstract

Diastereomeric 2-sulfonyloxaziridines (~)-{S,S)-1 and (+)-(R,R)-2 epoxidize unfunctionalized olefins 3a-g, affording epoxides 4a-g with better enantioselectivity than do chiral peracids or hydroperoxides. The configuration of the oxaziridine three-membered ring controls the stereochemistry of the product. The mechanism of chiral recognition is largely determined by steric factors where the orientations of the oxaziridine three-membered ring and the alkene are planar in the transition state. © 1983, American Chemical Society. All rights reserved.