## Abstract For Abstract see ChemInform Abstract in Full Text.
Synthesis of a tri- and a tetra-saccharide fragment of the capsular polysaccharide of type III group B Streptococcus
β Scribed by Vince Pozsgay; Jean-Robert Brisson; Harold J. Jennings
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 827 KB
- Volume
- 205
- Category
- Article
- ISSN
- 0008-6215
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β¦ Synopsis
Syntheses of the propyl glycosides (1-3) of beta-D-Galp-(1----4)-beta-D-GlcpNAc, beta-D-Glcp-(1----6)-[beta-D-Galp-(1----4)]-beta-D-GlcpNAc, and beta-D-Galp-(1----4)-beta-D-Glcp-(1----6)-[beta-D-Galp-(1----)]-beta-D- GlcpNAc, respectively, are reported. Reaction of allyl 2-acetamido-3-O-benzyl-2-deoxy-6-O-(4-methoxybenzyl)-beta-D-glucopyranos ide with 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide under Hg(CN)2 catalysis, followed by oxidative removal of the 4-methoxybenzyl group, gave allyl 2-acetamido-3-O-benzyl-2-deoxy-4-O-(2,3,4,6-tetra-O-acetyl-beta-D- galactopyranosyl)-beta-D-glucopyranoside (10) O-deacetylation of which, followed by hydrogenolysis/hydrogenation, gave 1. Reaction of 10 with beta-D-glucopyranose penta-acetate and beta-lactose octa-acetate, under catalysis by trimethylsilyl trifluoromethanesulfonate, and treatment of the products as for 10 gave 2 and 3, respectively. Attempted glycosylation of 10 with 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl bromide under catalysis by Hg(CN)2 or silver trifluoromethanesulfonate gave an orthoester. Complete assignments of the 1H- and 13C-n.m.r. spectra of 1-3 are reported together with their carbon spin-lattice relaxation times which indicate that 3 assumes a compact instead of an extended shape.
π SIMILAR VOLUMES
## Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a βFull Textβ option. The original article is trackable v
Methyl 2-acetamido-4-amino-2,4,6-trideoxy-3-0-(~-D-galactopyranosyl-uronit acid)-cY-D-galactopyranoside has been synthesised. The parent disaccharide is a structural element of the capsular polysaccharide antigen of Streptococcus pneumoniae type 1.
Methyl 4-(3-deoxy-L-glycero-tetronamido)-4,6-dideoxy-2-O-methyl-alpha-D- mannopyranoside was acetylated, and the fully protected methyl glycoside was treated with dichloromethyl methyl ether-ZnCl2 (DCMME-ZnCl2) reagent to give 3-O-acetyl-4-(2,4-di-O-acetyl-3- deoxy-L-glycero-tetronamido)-4,6-dideoxy
Syntheses of methyl 2-O-&I\_-rhamnopyranosyl-PD-galactopyranoside (9), methyl 2-O-cr-L-rhamnopyranosyl-/3-D-galactopyranoside (l3), and methyl 4-O-/3-D-glucopyranosyl-2-O-a-L-rhamnopyranosyl-BD-galactopyranoside ( 16) in good yields are described. Both 13 and 16 significantly inhibit antigen-antibod