Synthesis of two phosphate-containing "heptasaccharide" fragments of the capsular polysaccharides of Streptococcus pneumoniae types 6A and 6B

Ted M. Slaghek*, Augustinus A.M. Mass, Johannis P. Kamerling, Johannes F.G. Vliegenthart

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

23 Citations (Scopus)

Abstract

The "heptasaccharides" O-α-d-galactopyranosyl-(1→3)-O-α-d-glucopyranosyl-(1→3)-α-β-l-rhamnopyranose 2″-[O-α-d-glucopyranosyl-(1→3)-O-α-l-rhamnopyranosyl- (1→3)-d-ribit-5-yl sodium phosphate] (25) and O-α-d-galactopyranosyl-1(1→3)-O-α-d-glucopyranosyl-(1→3)-α,β-l -rhamnopyranose 2'-[O-α-d-galactopyranosyl-(1→3)-O-α-d-glucopyranosyl-(1→3)-O-α-l-rhamnopyranosyl-(1→4)-d- ribit-5-yl sodium phosphate (27), which are structural elements of the capsular polysaccharides of Streptococcus pneumoniae types 6A and 6B {[→2)-α-d-Galp-(1→3)-α-d-Glcp-(1→3)-α-l-Rhap- (1→X)-d-RibOH-(5-P→/]n;6AX = 3, 6BX = 4}, respectively, have been synthesized. 2,4-Di-O-acetyl-3-O-[2,4,6-tri-O-acetyl-3- O-(2,3,4,-tetra-O-acetyl-α-d-galactopyranosyl)-α-d-rhamnopyranosyl trichloroacetimidate (13) was coupled with 5-O-allyloxycarbonyl-1,2,4-tri-O-benzyl-d-ribitol (10), using trimethylsilyl triflate as a promotor (→14), and deallyloxycarbonylation (→15) and conversion into the corresponding triethylammonium phosphonate then gave 16. Condensation of 16 with 4-methoxybenzyl 2,4-di-O-benzyl-3-O-[2,4,6-tri-O-benzyl-3-O-(3,4,6-tri-O-benzyl-α-d-galactopyranosyl)-α-d-glucopyranosyl-α-l- rhamnopyranoside (22) followed by oxidation and deprotection afforded 25. 5-O-Allyl-1-O-allyloxycarbonyl-2,3-di-O-benzyl-d- ribitol (12) was coupled with 13, using trimethylsilyl triflate as a promoter, the resulting tetrasaccharide-alditol derivative 17 was deallyloxycarbonylated (→18), acetylated (→19), and deallylated (→20), and the product was converted into the triethylammonium phosphonate derivative 21. Condensation of 21 with 22 followed by oxidation and deprotection afforded 27.

Original languageEnglish
Pages (from-to)25-39
Number of pages15
JournalCarbohydrate Research
Volume211
Issue number1
DOIs
Publication statusPublished - 2 Apr 1991
Externally publishedYes

Fingerprint Dive into the research topics of 'Synthesis of two phosphate-containing "heptasaccharide" fragments of the capsular polysaccharides of Streptococcus pneumoniae types 6A and 6B'. Together they form a unique fingerprint.

Cite this