A short, versatile, and diastereoeelective method of preparing carbacephems has been developed. The procedure involves as a key step the aldol condensation of a protected glycine compound with a suitably designed aldehyde. In this step, most of the carbon skeleton of the carbacephem is assembled, and the two stereocentera of the final bicyclic@- lactam are set. This step also provides well-placed and synthetically useful functionality for ...