Total Synthesis of Tri-, Hexa- and Heptasaccharidic Substructures of the O-Polysaccharide of Providencia rustigianii O34 |
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Authors: | Dr Somayeh Ahadi Dr Shahid I Awan Prof Dr Daniel B Werz |
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Institution: | 1. Technische Universität Braunschweig, Institute of Organic Chemistry, Hagenring 30, 38106 Braunschweig, Germany;2. Georg-August-Universität Göttingen, Institute of Organic and Biomolecular Chemistry, Tammannstraße 2, 37077 Göttingen, Germany
These authors contributed equally to this work. |
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Abstract: | A general and efficient strategy for synthesis of tri-, hexa- and heptasaccharidic substructures of the lipopolysaccharide of Providencia rustigianii O34 is described. For the heptasaccharide seven different building blocks were employed. Special features of the structures are an α-linked galactosamine and the two embedded α-fucose units, which are either branched at positions-3 and -4 or further linked at their 2-position. Convergent strategies focused on 4+3], 3+4], and 4+2+1] couplings. Whereas the 4+3] and 3+4] coupling strategies failed the 4+2+1] strategy was successful. As monosaccharidic building blocks trichloroacetimidates and phosphates were employed. Global deprotection of the fully protected structures was achieved by Birch reaction. |
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Keywords: | fucose glycosylation lipopolysaccharide (LPS) oligosaccharides Providencia rustigianii |
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