1. Synthesis of the tetrasaccharide repeat unit of the O-antigen polysaccharide from Escherichia coli O77 employing the 2′-carboxybenzyl glycoside
- Author
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Heung Bae Jeon, Joo Mi Jeon, Bo Ram Lee, Kwan Soo Kim, and Jae Hyuk Jung
- Subjects
Carboxybenzyl ,chemistry.chemical_classification ,Glycosylation ,Stereochemistry ,Organic Chemistry ,Glycoside ,General Chemistry ,medicine.disease_cause ,Polysaccharide ,Catalysis ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Antigen ,medicine ,Tetrasaccharide ,Escherichia coli ,Repeat unit - Abstract
The synthesis of the suitably protected form (1) of the tetrasaccharide repeat unit, →2)-α-D-Manp-(1→2)-β-D-Manp-(1→3)-α-D-GlcpNAc-(1→6)-α-D-Manp-(1→ (A), of the O-antigen polysaccharide of the lipopolysaccharide from Escherichia coli O77 has been accomplished by latentactive glycosylation employing the 2′-carboxybenzyl (CB) gly coside method. In addition to previously used latent glycosyl donors, 2′-(benzyloxycarbonyl)benzyl (BCB) glycosides, new latent glycosyl donors, 2'-(allyloxycarbonyl)benzyl (ACB) glycosides, have been introduced as a direct precursor for the active CB glycosides. We also demonstrate that 4,6-O-benzylidene-2-azido-2-deoxy-α-D-mannopyranoside (7) has been readily prepared from D-glucosamine in good yield.Key words: Escherichia coli O77, glycosylation, 2′-carboxybenzyl (CB) glycosides, 2′-(allyloxycarbonyl)benzyl (ACB) glycosides, glycosyl donor.
- Published
- 2006