The water-soluble polymer, poly(2,3-dihydroxypropyl methacrylate), also known as poly(glyceryl methacrylate), is known to isomerize and give a mixture of 2,3- and 1,3-isomers in both the monomeric and polymeric forms. The glyceryl methacrylate monomer was synthesized via acid-catalyzed hydrolysis of glycidyl methacrylate, which produced a mixture of 1,3- and 2,3-isomers in a ratio of 25% and 75%, respectively. This was surprising, as hydrolysis of epoxy compounds generally yields a 1,2-diol product. Furthermore, the level of 1,3-isomer at equilibrium is known to be 10% in both the glyceryl methacrylate monomer and polymer. An alternative hydrolysis pathway involving the ester and epoxy moieties was investigated for glycidyl methacrylate, and a mechanism was proposed. (c) 2006 Elsevier Ltd. All rights reserved.