This article reports the synthesis and copolymerization of 6-hydroxynon-8-enoic acid lactone. The ring-opening polymerization of this lactone-type monomer bearing a pendant allyl group led to new homopolymers and random copolymers with epsilon-caprolactone and L,L-lactide. The copolymerizations were carried out at 110 degrees C with Sn(Oct)(2) as a catalyst. The introduction of unsaturations into the aliphatic polyester permitted us to carry out different chemical transformations on this family of polymers. For example, this article reports the bromination, epoxidation, and hydrosylilation of the allyl group in the new polyester copolymers.