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

The asymmetric aldol reaction of a tetra substituted ketene silyl acetal including an alkylseleno group with aldehydes is developed by the promotion of the 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 alpha-methylene-beta-hydroxy esters, which correspond to adducts prepared by the asymmetric Morita-Baylis-Hillman reaction.