Synthesis of S-Linked Thiooligosaccharide Analogues of Nodulation Factors. 2.1 Synthesis of an Intermediate Thiotrisaccharide
| Autor: | Jacques Gelas, Jean-Claude Promé, France-Isabelle Auzanneau, Danielle Promé, Monia Mialon |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | The Journal of Organic Chemistry. 63:6460-6465 |
| ISSN: | 1520-6904 0022-3263 |
| Popis: | An S-linked thiotrisaccharide analogue of chitin that carries different N-protecting groups at the reducing and nonreducing end glucosamine residues was prepared as an intermediate for the synthesis of thioanalogues of nodulation factors. 1,6-Anhydro-2-azido-3-O-benzoyl-2-deoxy-β-d-glucopyranose (3) was prepared either through the nucleophilic displacement of the 4-triflate galacto analogue 1 with potassium chloroacetate or via the selective acylation of the analogous gluco diol 4. Condensation of 3 with the N-phthalimido trichloroacetimidate 9 led to the disaccharide 10, which was converted in four steps to the glucosyl bromide 15. Nucleophilic displacement of the anomeric bromide by a 4-thiolate derivative of glucosamine (16) bearing a trichloroethoxycarbamate at C-2 was performed in anhydrous oxygen-free THF and led to the desired thiotrisaccharide precursor of thioanalogues of nodulation factors. Alternatively, the disaccharide 10 was prepared by regioselective glycosylation of the 1,6-anhydro diol 4 ... |
| Databáze: | OpenAIRE |
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