Syntheses of Polypeptides by Hydrogenolysis of N-Benzyloxycarbonyl-Amino Acid Anhydrides

When anhydrides of N-benzyloxycarbonyl-Dl-aspartic acid (Z-Dl-Asp), Z-l-Asp, N-Z-Dl-glutamic acid (Z-Dl-Glu), Z-l-Glu, and N-Z-3-aminoglutaric acid (Z-β-Agl) were hydrogenolyzed in N,N dimethylformamide (DMF), polypeptides were obtained in high yields. Hydrogenolyses of Z-Dl-Glu and Z-l-Glu in dioxane gave pyroglutamic acid.