Polymerization of lactides and lactones, 12. Synthesis of poly[(glycolic acid)-alt-(<SC>L</SC>-glutamic acid)] and poly{(lactic acid)-co-[(glycolic acid)-alt-(<SC>L</SC>-glutamic acid)]}

Glutamic acid/glycolic acid-based biodegradable polymers have been prepared by ring-opening polymerization of (3S)-3-[(benzylcarbonyl)ethylene] morpholine-2,5-dione, and the copolymerization of the morpholine-2,5-dione derivative and lactide. The homopolymerization and copolymerization were carried out in bulk at 140°C with SnOct<INF>2</INF> as a catalyst to give the corresponding protected poly(Glc-alt-Glu) and protected poly[LA-co-(Glc-alt-Glu)], respectively. After removal of the protective group by catalytic hydrogenation with Pd/C (5%) as a catalyst, poly(Glc-alt-Glu) and poly[LA-co-(Glc-alt-Glu)] showed excellent hydrophilicity.