A hydroxylactone ((1R,5S)-1-hydroxy-3,6-dioxabicyclo [3.2.1] octan-2-one, abbreviated as LAC) obtained from catalytic pyrolysis of cellulose was investigated as a monomer in the synthesis of polyesters by ring-opening polymerization (ROP) with L-lactide. Although stannous octoate resulted inactive, ROP initiated by zirconium (TV) acetylacetonate afforded novel copolyesters from LAC and lactide mixtures in the bulk at 110 degrees C. Copolymers were obtained with different LAC content (from 19 to 45%) with a random microstructure as established by detailed NMR analysis. FTIR spectrometry confirmed the presence in the polymer chain of the OH groups originally present in LAC, which do not react during polymerization due to steric hindrance and inter/intramolecular hydrogen bonding. Reaction with trichloroacetylisocyanide proved that OH groups of the polyesters can be readily derivatized. The application of LAC as a comonomer enables the insertion of the alcohol functionality in polylactide avoiding protection/deprotection steps and potentially expanding the realm of biomaterials affordable from carbohydrate feedstock. (c) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 247-257, 2009