Direct vinylogous aldol addition of γ-butyrolactones and γ-butyrolactams

Deprotonation of N-benzyl-3-phenylselenylpyrrol-2(5H)-one 3 and furan-2(5H)-one 4 and reaction with aldehydes affords regioselectively 5-(1′-hydroxy)-γ-butyrolactones and the aza-analogous butyrolactams with good diastereoisomeric excesses. The presence of Lewis acids enhances the diastereoisomeric ratios. ethodology is an alternative to Lewis acid mediated silyloxydiene condensation.