Synthesis of (1 -> 4)-β-D-xylo-oligosaccharides of dp 4-10 by a blockwise approach

Article abstract of DOI:10.1016/0008-6215(95)00259-6

Dibutyltin oxide-mediated regioselective chloroacetylation of methyl 1-thio-β-xylobioside, followed by treatment of the product with 4-methylbenzoyl chloride-pyridine, gave methyl 4-O-chloroacetyl-2,3-di-O-(4-methylbenzoyl)-β-D-xylopyranosyl-(1 -> 4)-2,3-di-O-(4-methylbenzoyl)-1-thio-β-D-xylopyranoside (18) in 70percent yield.Coupling of 18 with benzyl alcohol afforded the disaccharide benzyl β-glycoside, which was O-dechloroacetylated to provide methyl 2,3-di-O-(4-methylbenzoyl)-β-D-xylopyranosyl-(1 -> 4)-2,3-di-O-(4-methylbenzoyl)-1-thio-β-D-xylopyranoside (20).A homologous series of (1 -> 4)-β-D-xylo-oligosaccharides from the tetra- to the deca-saccharide have been synthesized in a blockwise manner by using 20 as the glycosyl acceptor, 18, methyl 1-thio-β-xylobioside pentaacetate, and methyl 1-thio-β-xylotrioside heptaacetate as the glycosyl donors, and a combination of N-iodosuccinimide-silver triflate as the promoter.Keywords: Oligosaccharides; D-xylo-; Synthesis, blockwise; Glycosidation