Syntheses of O-beta-D-Mannosyl-(1à4)-O-alpha-D-mannosyl-(1à3)-L-rhamnose and O-(2-Acetamido-2-deoxy-beta-D-mannosyl)-(1à4)-O-alpha-D-galactosyl-(1à4)-D-galactose via In-situ-activating Glycosylation Using 2-O-Acetyl-3,4,6-tri-O-benzyl-D-glucose

摘要

O-beta-D-Mannopyranosyl-(1à4)-O-alpha-D-mannopyranosyl-(1à3)-L-rhamnopyranose,a trisaccharide including a repeating unit of the O-specific polysaccharide(OSP)of Bulkholderia vietnamiensis strain LMG 6988,and O-(2-acet-amido-2-deoxy-beta-D-mannopyranosyl)-(1à4)-O-alpha-D-glactopyranosyl-(1à4)-D-galactopyranose,a trisaccharide including a repeating unit of OSP of Acinetobactor baumannii serogroup O18,were synthesized by means of in-situ-activating glycosylation using 2-O-acetyl-3,4,6-tri-O-benzyl-D-glucopyranose(2ATBG)and a reagent mixture of pnitrobenzenesulfonyl chloride,silver triflate,and 1,8-diazabicyclo[5.4.0]undec-7-ene,and related systems.New syntheses of 2ATBG,ally 2,3,6-tri-O-benzyl-alpha-D-galactopyranoside,benzyl 2,3,6-tri-O-benzyl-alpha-D-galactopyranoside,and 2-azido-3,4,6-tri-O-benzyl-2-deoxy-D-mannopyranose are described.