Acetolysis of methyl 4-O-(2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-β-D-mannopyranosyl)-2,3,6-triO-benzyl-α-D-glucopyranoside (3) followed by treatment with hydrogen bromide–acetic acid afforded 4-O-(2-acetamido-6-O-acetyl-3,4-di-O-benzyl-2-deoxy-β-D-mannopyranosyl)-6-O-acetyl-2-O-benzyl-α-D-glucopyranosyl bromide (5). Compound (5) by Hg(CN)2–HgBr2 promoted condensation with benzyl 3,4-di-O-benzyl-α-L-rhamnopyranoside (6) provided the glycosylation product (22% yield) exclusively in the α-configuration. Hydrogenolysis of the benzyl protecting groups of the obtained trisaccharide and O-deacetylation of the 6′ and 6″ positions eventually furnished O-(2-acetamido-2-deoxy-β-D-mannopyranosyl)-(1→4)-O-α-D-glucopyranosyl-(1→2)-α,β-L-rhamnopyranose (1), the trisaccharide component of the repeating unit of Streptococcus pneumoniae type 19F.
Synthesis of the trisaccharide component of the repeating unit of the capsular polysaccharide of Streptococcus pneumoniae type 19F / L. Panza, F. Ronchetti, G. Russo, L. Toma. - In: JOURNAL OF THE CHEMICAL SOCIETY. PERKIN TRANSACTIONS. I. - ISSN 0300-922X. - 0(1987), pp. 2745-2747. [10.1039/p19870002745]
Synthesis of the trisaccharide component of the repeating unit of the capsular polysaccharide of Streptococcus pneumoniae type 19F
F. RonchettiSecondo
;G. RussoPenultimo
;
1987
Abstract
Acetolysis of methyl 4-O-(2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-β-D-mannopyranosyl)-2,3,6-triO-benzyl-α-D-glucopyranoside (3) followed by treatment with hydrogen bromide–acetic acid afforded 4-O-(2-acetamido-6-O-acetyl-3,4-di-O-benzyl-2-deoxy-β-D-mannopyranosyl)-6-O-acetyl-2-O-benzyl-α-D-glucopyranosyl bromide (5). Compound (5) by Hg(CN)2–HgBr2 promoted condensation with benzyl 3,4-di-O-benzyl-α-L-rhamnopyranoside (6) provided the glycosylation product (22% yield) exclusively in the α-configuration. Hydrogenolysis of the benzyl protecting groups of the obtained trisaccharide and O-deacetylation of the 6′ and 6″ positions eventually furnished O-(2-acetamido-2-deoxy-β-D-mannopyranosyl)-(1→4)-O-α-D-glucopyranosyl-(1→2)-α,β-L-rhamnopyranose (1), the trisaccharide component of the repeating unit of Streptococcus pneumoniae type 19F.Pubblicazioni consigliate
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