Synthesis and glycosylation of pyrimidin-2-yl 1-thio-α-d-manno- and -α-l-rhamnopyranoside
摘要:
Pyrimidin-2-yl 2,3,4,6-tetra-O-benzyl-1-thio-alpha-D-mannopyrano side (9), pyrimidin-2-yl 2,3,4-tri-O-benzyl-alpha-L-rhamnopyranoside (10), pyrimidin-2-yl 2-O-acetyl-3,4,6-tri-O-benzyl-1-thio-alpha-D-mannopyranoside (7), and pyrimidin-2-y1 2-O-acetyl-3,4-di-O-benzyl-1-thio-alpha-L-rhamnopyranoside (8) were prepared almost quantitatively fi om the corresponding protected 1,2-O-methoxyethylidene-beta-D-manno-or-beta-L-rhamnopyranose with 2-mercaptopyrimidine in the presence of mercuric bromide. Coupling reactions of the thioglycosides promoted by silver triflate with suitable glycosyl accepters afforded 1,2-trans linked disaccharides. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.
A facile method for the preparation of sugar orthoesters promoted by anhydrous sodium bicarbonate
作者:Shanqiao Wei、Jinzhong Zhao、Huawu Shao
DOI:10.1139/v09-146
日期:2009.12
A facile and eco-friendly method for the preparation of sugar orthoesters by using anhydroussodium bicarbon- ate is described. Various sugar orthoesers, including sugar-sugar orthoesters, were synthesized in good-to-excellent yields by the reaction of a protected glycosyl bromide with an alcohol or sugar.
A convenient and alternative procedure for the synthesis of sugarorthoesters from glycosyl bromides with anhydrous sodium acetate as base under ultrasound irradiation is described. Various sugar and sugar‐sugarorthoesters were prepared in 70&percnt–91&percnt isolated yields.
1,2-O-(1-Methoxyethylidene) derivatives of hexopyranoses can be converted to the corresponding trans-1,2-diacetates in a highly stereoselective manner by treatment with trimethylsilyl acetate. O-Acetyl, O-benzyl and O-isopropylidene groups are stable under the reaction conditions.
Synthesis of a Tri- and Tetrasaccharide Fragment Specific for the <i>Shigella flexneri</i> Serotype 5a <i>O</i>-Antigen. A Reinvestigation
作者:Laurence A. Mulard、Joël Ughetto-Monfrin
DOI:10.1080/07328309908544033
日期:1999.1.1
Stereocontrolled, stepwise synthesis of methyl α-L-rhamnopyranosyl-(1→2)-[α-D-glucopyranosyl-(1→3)]-α-L-rhamnopyranoside (A(E)B, 1) and methyl2-acetamido-2-deoxy-β-D-glucopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→2)-[α-D-glucopyranosyl-(1→3)]-α-L-rhamnopyranoside (DA(E)B, 2) is described; these constitute the methyl glycosides of fragments of the O-specific polysaccharide of Shigella flexneri serotype
Chemical Synthesis of the Trisaccharide Epitope of Phenolic Glycolipid-1 Surface Antigen from <i>Mycobacterium leprae</i>
作者:Wan-Yue Luo、Bin Lu、Rong-Ye Zhou、Xiao Hu、Jin Wang
DOI:10.1021/acs.joc.0c01088
日期:2020.8.21
PGL-1 epitope 1 bearing a p-aminoethylphenol group was efficiently synthesized by using linear synthetic routes. A method for efficient synthesis of oligosaccharides containing rhamnose rings was developed. The chemistry is flexible and could be used for the synthesis of other PGLs antigens. A biotinylated PGL-1 antigen 23 was synthesized and could be used as a probe for early detection of leprosy.