Dual enantioselective Diels-Alder process in the cyclization of chiral acrylamide with dienes

Abstract

Diels-Alder cycloadditions of chiral acrylamides with cyclopentadiene or 2, 3-dimethyl butadiene proceed with high diastereofacial selectivity. Either endo-R or endo-S products have been obtained depending upon the structures of acrylamides and Lewis acids used. The endo form was exclusively obtained over the exo form. The dependence of the mechanism of formation of opposite configurations of endo-R or endo-S products on the Lewis acids is discussed. Copyright (C) 2004 John Wiley Sons, Ltd.