REGIOSELECTIVE SYNTHESIS OF ETHOXYLATED GLYCOSIDE ESTERS USING BETA-GLUCOSIDASE IN SUPERSATURATED SOLUTIONS AND LIPASES IN ORGANIC-SOLVENTS

Three ethoxylated glycosides, tetraethylene glycol beta-D-glucoside, t etraethylene glycol beta-D-xyloside, and methoxy triethyleneglycol bet a-D-glucoside, were prepared via almond beta-glucoside-catalyzed (tran s)glycosylation carried out in supersaturated solutions of glucose or p-nitrophenyl beta-D-xyloside and the respective polyethylene glycols. The products were isolated and further modified by enzymatic esterifi cation with Candida antarctica and Mucor miehei lipases. The latter en zyme showed a much greater selectivity for the primary hydroxyl group on the polyethylene glycol chain of the glucoside substrate, thus enab ling us to obtain exclusively the corresponding monoester, omega-O-ole oyl tetraethylene glycol beta-D-glucoside. Novozyme was used for the p reparative synthesis of two other monoesters, 6-O-oleoyl (methoxy trie thyleneglycol) beta-D-glucoside and omega-O-oleoyl tetraethylene glyco l beta-D-xyloside, Two diesters, di-oleoyl tetraethylene glycol beta-D -glucoside and tetraethylene-bis(6-0-oleoyl glucoside) were also synth esized in good yields using this lipase. (C) 1998 John Wiley & Sons, I nc.