title: Synthesis of oligosaccharides corresponding to Streptococcus pneumoniae type 9 capsular polysaccharide structures.
abstract: Two trisaccharides, alpha-D-Galp-(1-->3)-beta-D-ManpNAc-(1-->4)-beta-D-Glcp and alpha-D-Glcp-(1-->3)-beta-D-ManpNAc-(1-->4)-beta-D-Glcp, corresponding to structures from Streptococcus pneumoniae capsular polysaccharides type 9A, L, V and type 9N, respectively, have been synthesised as 2-aminoethyl glycosides and as protected TMSE glycosides. Ethyl thioglycosides were used as glycosyl donors and NIS/TfOH (in CH(2)Cl(2) for beta-linkages) and DMTST (in Et(2)O for alpha-linkages) as promoters in the glycosylations. The beta-ManNAc motif was introduced at the disaccharide level by azide displacement of a 2-O-triflate with beta-D-gluco configuration. The protecting group patterns allow continued syntheses of larger structures.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91, Stockholm, Sweden.
authors.forename: Mia
authors.initials: M
authors.lastname: Alpe
authors.forename: Stefan
authors.initials: S
authors.lastname: Oscarson
mesh_terms: D016667:Bacterial Capsules / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002855:Chromatography, Thin Layer; D006027:Glycosides / Q000737:chemistry; D006031:Glycosylation; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis*; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D013296:Streptococcus pneumoniae / Q000737:chemistry* / Q000145:classification / Q000472:pathogenicity; D014312:Trisaccharides / Q000138:chemical synthesis
chemical_list: D006027:Glycosides; D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial; D014312:Trisaccharides