Asymmetric Induction Reactions. II. Stereochemical Studies on Asymmetric [2, 3] Sigmatropic Rearrangements Using Chiral Ketenimines

Abstract

Stereochemical studies were performed on asymmetric [2, 3] sigmatropic rearrangements of sulfur ylides derived from chiral ketenimines possessing various kinds of substituents and prochiral sulfur ylides. A mechanistic pathway for these rearrangements is proposed on the basis of the stereochemical results obtained. New asymmetric centers are induced on the sulfur atoms of the ylides during the reactions.