2,3-Anhydro Sugars in Glycoside Bond Synthesis. Highly Stereoselective Syntheses of Oligosaccharides Containing α- and β-Arabinofuranosyl Linkages
作者:Rajendrakumar Reddy Gadikota、Christopher S. Callam、Timothy Wagner、Brian Del Fraino、Todd L. Lowary
DOI:10.1021/ja029302m
日期:2003.4.1
biologically important events mediated by carbohydrates has generated great interest in the synthesis of oligosaccharides and the development of new methods for glycosidic bond formation. In this paper, we report that 2,3-anhydrofuranose thioglycosides (1, 5) and glycosyl sulfoxides (2, 6), in which the hydroxyl groups C-2 and C-3 are “protected” as an epoxide, glycosylate alcohols with an exceptionally
Arabinofuranosides from Mycobacteria: Synthesis of a Highly Branched Hexasaccharide and Related Fragments Containing β-Arabinofuranosyl Residues
作者:Haifeng Yin、Francis W. D'Souz、Todd L. Lowary
DOI:10.1021/jo010910e
日期:2002.2.1
The synthesis of 11 oligosaccharides (4-14) containing beta-arabinofuranosyl residues is reported. The glycans are all fragments of two polysaccharides, arabinogalactan and lipoarabinomannan, which are found in the cell wall complex of mycobacteria. In the preparation of the targets, the key step was a low-temperature glycosylation reaction that installed the beta-arabinofuranosyl residues with good
β-Arabinofuranosylation Using 5-<i>O</i>-(2-Quinolinecarbonyl) Substituted Ethyl Thioglycoside Donors
作者:Qiang-Wei Liu、Hua-Chao Bin、Jin-Song Yang
DOI:10.1021/ol401755e
日期:2013.8.2
A new β-stereoselective d- and l-arabinofuranosylation method has been developed employing 5-O-(2-quinolinecarbonyl) substituted arabinosyl ethylthioglycosides as glycosyl donors. The approach allows a wide range of acceptor substrates to be used; the β-selectivity is good-to-excellent. Stereoselective synthesis of a mannose-capped octasaccharide portion from a mycobacterial cell wall polysaccharide
their significance in controlling disease spurred interest in developing strategies for their diastereoselective synthesis. Mtb uses enzymes to achieve diastereoselectivity through noncovalent interactions. Of the two possible glycosidic linkages, chemically, 1,2-trans linkage is relatively easy to synthesize by taking advantage of neighboringgroupparticipation, whereas synthesis of the 1,2-cis linkage