Synthesis of novel hydrophilic biodegradable polyester with functionalizedside chain groups

A substituted glycolide, 3-benzyloxymethyl-1,4-dioxane-2,5-dione, was synth esized. It is a suitable precursor for the preparation of a new hydrophilic biodegradable poly(a-hydroxy acid). The polymerizations were carried out i n bulk in the presence of Sn(Oct)(2) at 120-140 degreesC. The resulting pol ymers were subjected to hydrogenolysis with a Pd/C catalyst in a mixed solv ent to remove the protecting benzyl groups. A novel poly(a-hydroxy acid) wi th pendant hydroxy groups was obtained. The hydrophilicity of the resulting polymer was evaluated preliminarily.