Phase-transfer-catalyzed asymmetric desymmetrizations of cyclopentanones

Abstract

Although various highly enantioselective transformations have been achieved under phase-transfer conditions, asymmetric desymmetrization of cyclic ketones is still a challenging reaction in the phase-transfer chemistry. In this context, we have developed asymmetric desymmetrization of meso-epoxy ketones under phase-transfer conditions. The epoxide-opening reaction was efficiently promoted by chiral bifunctional phase-transfer catalysts to give the corresponding cyclic ketones with high enantioselectivities. Furthermore, this reaction system was applied to asymmetric isomerization of cyclic ketone.