Enantioselective synthesis of the optically active alpha-methylene-beta-hydroxy esters, equivalent compounds to Morita-Baylis-Hillman adducts, using successive asymmetric aldol reaction and oxidative deselenization

摘要

The asymmetric aldol reaction of a tetra-substituted ketene silyl acetal including an alkylseleno group with aldehydes has been developed by the promotion of Sn(OTf)(2) coordinated with a chiral diamine to afford the corresponding aldols having chiral quaternary centers at the alpha-positions. The facile oxidative deselenization of these aldol compounds produces optically active beta-methyleneP-hydroxy esters which correspond to adducts prepared by the asymmetric Morita-Baylis-Hillman reaction.