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A highly stereoselective construction of 1,2-trans-β-glycosidic linkages capitalizing on 2-azido-2-deoxy-D-glycosyl diphenyl phosphates as glycosyl donors
| Title: | A highly stereoselective construction of 1,2-trans-β-glycosidic linkages capitalizing on 2-azido-2-deoxy-D-glycosyl diphenyl phosphates as glycosyl donors |
| Authors: | Tsuda, Toshifumi1 Browse this author | | Nakamura, Seiichi2 Browse this author | | Hashimoto, Shunichi3 Browse this author →KAKEN DB |
| Authors(alt): | 津田, 敏史1 | | 中村, 精一2 | | 橋本, 俊一3 |
| Keywords: | 2-Azido-2-deoxyglycopyranosyl diphenyl phosphate | | β-Selective glycosidation | | α-Nitrilium ion |
| Issue Date: | 1-Oct-2004 |
| Publisher: | Elsevier |
| Journal Title: | Tetrahedron |
| Volume: | 60 |
| Issue: | 47 |
| Start Page: | 10711 |
| End Page: | 10737 |
| Publisher DOI: | 10.1016/j.tet.2004.08.076 |
| Abstract: | The scope of TMSOTf-promoted glycosidation of 2-azido-2-deoxyglycopyranosyl diphenyl phosphates is investigated. The 3,4,6-tri-O-benzyl-protected glucosyl and galactosyl donors and the 4,6-O-benzylidene-protected galactosyl donor each react with a range of acceptor alcohols in the presence of a stoichiometric amount of TMSOTf in propionitrile at -78 °C to afford 1,2-trans-β-linked disaccharides in high yields with α:β ratios ranging from 9:91 to 1:>99, regardless of the anomeric composition of the donor used. The use of propionitrile as a solvent at -78 °C has proven to be among the best choice for the highest levels of β-selectivity reported to date for this type of glycosidation. A plausible reaction mechanism, which features a large equilibrium preference for α-glycosyl-nitrilium ions over β-nitrilium ions, is proposed based on byproducts formed through their intermediacy and accounts for the observed excellent β-selectivities. |
| Relation: | http://www.sciencedirect.com/science/journal/00404020 |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/614 |
| Appears in Collections: | 薬学研究院 (Faculty of Pharmaceutical Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 中村 精一
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