Polydepsipeptides I. Synthesis and Characterization of Copolymers of α‐Amino and α‐Hydroxy Acids

Copolymers of the type (Formula Presented.) were synthesized and characterized. The syntheses of these copolymers were achieved by copolymerization of an α‐amino acid N‐carboxy anhydride and an α‐hydroxy acid anhydrosulfite in the presence of a catalyst. The copolymers were characterized by spectroscopic methods including infrared, circular dichroism and nuclear magnetic resonance. Specific cleavage of the ester bonds by hydroxylamine in the cold confirmed the A‐B block structure where the A represents the poly(amino acid) segment and the B indicates the polyester segment. Measurements by nmr and viscosity indicate that the blocks consist of short chain lengths.