Stereoselective Synthesis of Enantiomerically Pure 4,5-Disubstituted Pyrrolidinones from β-Amino Esters.

Abstract α-Alkylation of N -tosyl-protected β-amino esters with LDA as the base led to high anti selectivity for the newly formed C–C bond. The α-alkylated β-amino esters were further transformed to enantiomerically pure 4,5-disubstituted pyrrolidinones through hydrolysis, diazotization, and Wolf rearrangement under AgO 2 CPh/Et 3 N/dry THF conditions.