Catalytic Enantioselective Synthesis of Chiral γ-Butyrolactones
摘要:
A tandem catalytic asymmetric aldol reaction/cyclization of beta,gamma-didehydro-gamma-lactones with aldehydes was achieved using chiral tin dibromide as a chiral precatalyst and sodium alkoxide as a base precatalyst. Optically active trans-beta,gamma-disubstituted gamma-butyrolactones were selectively obtained in moderate to high yields with up to 99% cc from gamma-aryl-substituted beta,gamma-didehydro-gamma-butyrolactones and bulky aliphatic aldehydes.