Patent ID: 6979720

Claim:
A process for the production of certain cyclic ester oligomers, comprising the step of: reacting, in a preselected solvent, components comprising: (1) a first component which is a linear ester oligomer derived from reactants comprising an aromatic dicarboxylic acid and a diol of the general formula HOCH 2 (CR 1 R 2 ) n CH 2 OH, wherein R 1 and R 2 are each independently hydrogen or an alkyl group and n is 0, 1 or 2, which first component has an average degree of polymerization of about 1.5 to about 10; in the presence of (2) a second component which is an enzyme capable of catalyzing transesterification of esters, with the proviso that if said first component has more than 5 mole percent carboxylic acid ends, said second component is also capable of catalyzing esterification of carboxylic acids; wherein said reacting step is carried out at a predetermined temperature at which said first component has a solubility of at least one w/v percent in said preselected solvent.