6-O-Vinylacetyl glucose was synthesized with an immobilized lipase using vinylacetic acid and glucose in water-miscible organic solvents, of which acetonitrile gave the highest conversion of 35% at 50 mM glucose and 600 mM vinylacetic acid. The addition of 3Angstrom molecular sieves at 60 mg ml(-1) increased the conversion to 74%. The product, 6-O-vinylacetyl glucose, was polymerized to yield a water-soluble polymer with a molecular mass of about 5000.