Syntheses of p-nitrophenyl 3- and 4-thio-β-d-glycopyranosides
作者:Hong-Ming Chen、Stephen G. Withers
DOI:10.1016/j.carres.2010.10.001
日期:2010.12
Thioglycosides have proved to be useful, enzymatically stable analogs of glycosides for structural and mechanistic studies and their synthesis is considerably simplified through the use of thioglycoligases. As part of an investigation into the use of thioglycosides as potential pharmacological chaperones, and as components of glycoproteins and glycolipids, the syntheses of p-nitrophenyl 3-thio-β-D-galactopyranoside
4-Nitrophenyl 3,4,6-tri-O-acetyl-2-azido-2-deoxy-alpha- and beta1-D-mannopyranosides were prepared from methyl 4,6-O-benzylidene-alpha-D-glucopyranoside and 1,3,4,6-tetra-O-acetyl-alpha-D-glucopyranose, respectively. Chemoselective reduction of both azides with hydrogen sulfide readily afforded 4-nitrophenyl 2-acetamido-4,6-di-O-acetyl-2-deoxy-alpha-D- and -beta-D-mannopyranosides in higher yields than reduction with triphenylphosphine or a polymer-supported triarylphosphine. Subsequent de-O-acetylation yielded 4-nitrophenyl 2-acetamido-2-deoxy-alpha-D-mannopyranoside and 4-nitrophenyl 2-acetamido-2-deoxy-beta-D-mannopyranoside in 20 % and 44 % overall yields, respectively. (C) 2004 Elsevier Ltd. All rights reserved.