Synthesis of poly(α‐malic acid) and its hydrolysis behavior in vitro

Biodegradable poly(α‐malic acid) ( 7 ) was synthesized by means of ring‐opening homopolymerization of malide dibenzyl ester ( 5 ), which is a cyclic dimer of β‐benzyl malate. In order to obtain a high‐molecular‐weight biodegradable lactic acid type polyester having pendent modifiable groups, ring‐opening copolymerization of malide dibenzyl ester with L ‐dilactide was applied to give poly(α‐malic acid‐ co ‐lactic acid) ( 10 ). It was found from the results of hydrolysis of poly(α‐malic acid) that the main‐chain ester bonds were cleaved randomly and slowly in vitro .