Cu(I)-Catalyzed Reductive Aldol Cyclizations:  Diastereo- and Enantioselective Synthesis of β-Hydroxylactones

Abstract

[reaction: see text] Copper bisphosphine complexes catalyze the intramolecular reductive aldol reaction of alpha,beta-unsaturated esters with ketones, affording five- and six-membered beta-hydroxylactones in high stereoselectivities. Utilization of chiral nonracemic bisphosphines render the cyclizations enantioselective.