Regioselective acylation of secondary hydroxyl groups in sugars catalyzed by lipases in organic solvents
Therisod, M.; Klibanov, A.M.
Journal of the American Chemical Society 109(13): 3977-3981
1987
ISSN/ISBN: 0002-7863 DOI: 10.1021/ja00247a024
Accession: 006285082
Several unrelated, commercially available lipases (porcine pancreatic, bacterial, yeast, and fungal) can catalyze transesterification reactions between trichloroethyl butyrate and monosaccharides with blocked C-6 hydroxyl groups (enzymatically acylated or chemically alkylated) in dry organic solvents. Lipases exhibit a remarkable regioselectivity by discriminating among the four available secondary hydroxyl groups in C-6 protected glucose, galactose, and mannose. While some lipases exclusively acylate the C-3 hydroxyl group, others display an overwhelming preference toward the C-2 hydroxyl group. This positional specificity of lipases was used for the preparation of various sugar diesters and, consequently, for either fully enzymatic or chemicoenzymatic preparative synthesis of C-2 or C-3 monoesters of glucose.