Synthesis of polyfunctional glycerol esters: Lipase-catalyzed esterification of glycerol with diesters

The enzymatic esterification of glycerol with dicarboxylic acids or esters was studied to produce mono- and/or diesterified glycerol adducts. Such mat erials are useful synthons in the synthesis of biodegradable polymers and s urfactants. In this work two strategies were studied for preparing these pr e-polymeric glycerol derivatives: the lipase-catalyzed esterification of fr ee glycerol with diacids or esters and the reaction of supported or protect ed glycerol with diesters. For example, reaction of isopropylidene glycerol with dimethyl sebacate gave a >95% yield of isopropylidene glycerol-monome thyl sebacate ester. Reaction of glycerol supported on silica with dimethyl adipate gave a 40% yield of glycerol-monomethyl adipate ester. Best yields of glycerol-mono- and diesters (70% and 10%, respectively) were obtained b y direct esterification of free glycerol with a diester in a solvent-free s ystem containing small amounts of water (<4%).