Preparation of Enantiomerically Pure β‐Silylcarboxyl Derivatives by Asymmetric 1,4‐Addition to <i>N</i>‐Enoyl‐sultams. Preliminary Communication

Abstract

Abstract EtAlCl 2 ‐promoted additions of organocopper reagents to camphor‐derived, conjugated N ‐enoyl‐sultams gave saturated and olefinic β‐silylcarboxyl derivatives with high diastereodifferentiation. Nondestructive removal of the chiral auxiliary followed by oxidative Si‐C bond cleavage furnished enantiomerically pure acetate‐derived aldols and propionate‐derived ‘ anti ’ ‐aldols ( via silyl‐directed α‐methylation).