Highly diastereoselective synthesis of beta-carboxy-gamma-lactams and their ethyl esters via Sc(OTf)(3)-catalyzed imino Mukaiyama-aldol type reaction of 2,5-bis(trimethylsilyloxy)furan with imines.

Functionalized gamma-lactams are found to be crucial intermediates in the synthesis of biologically important natural products. We herein described a highly diastereoselective synthesis of beta-carboxy-gamma-lactams and their ethyl ester derivatives, in high yields with high diastereomeric ratio, via the Mukaiyama-aldol type reaction of 2,5-bis(trimethysilyloxy)furan with imines, employing Sc(OTf)(3) as a catalyst.