Enzymic glycosylation using 6-substituted glycosides as donor substrates: a novel route to functionalised disaccharides

Abstract

The ability of functionalised monosaccharides 1–10, which include both natural and unnatural derivatives, to act as donors in glycosidase-mediated glycosylation processes has been evaluated. Using methyl α-D-galactopyranoside as the acceptor, the glycosidase-containing preparations snail acetone powder and barley extract catalysed formation of 1→4 and 1→6 disaccharides, respectively, with good to excellent levels of regioselectivity. With disaccharide formation achieved, the ability to harness the functionality resident within the donor component has been demonstrated by (i) selective reduction of the alkyne moiety of compound 19 and (ii) dihydroxylation of alkene 21.