A β-lactam route to short peptide segments related toAngiotensin-Converting Enzyme (ACE) inhibitors

Abstract

The stereocontrolled synthesis of the Angiotensin Converting Enzyme (ACE) inhibitor enalapril is reported. The key transformation of the synthesis is a formal carboxylation of imines, which lies in the sequence: imine-ketene [2+2] cycloaddition reaction, ring expansion of the resulting 3-hydroxy β-lactam to a N-carboxy α-amino acid anhydride (NCA), and final opening of the NCA with alcohols.