Dehydrative Polycondensation of (R)-3-Hydroxybutyric Acid with an Acid/Phosphine System: Formation of OH/COOH Telechelic Biodegradable Polyester

A biodegradable poly((R)-3-hydroxybutyrate) was synthesized by acid-catalyzed dehydrative polycondensation of (R)-3-hydroxybutyric acid. The addition of polymer-bound triphenyl-phosphine as a crotonoyl scavenger prevented end capping by the crotonoyl group. After the removal of phosphine by simple filtra-tion, a telechelic polyester bearing carboxy and hydroxy groups at the two termini was obtained. These results provide a new strategy for the copolymerization of poly(3-hydroxybutyrate).