Synthesis of spacer-containing di- and tri-saccharides that represent parts of the capsular polysaccharide of Streptococcus pneumoniae type 6B.

In the framework of studies towards oligosaccharide-conjugate-based vaccines against Streptococcus pneumoniae, the synthesis is reported of several spacer-containing oligosaccharides that represent parts of the capsular polysaccharide of S. pneumoniae serotype 6B, namely alpha-L-rhamnopyranosyl-(1-->4)-5-O-(3-aminopropyl hydrogen phosphate)-D-ribitol, 3-aminopropyl D-ribitol-(5-->hydrogen phosphate-->2)-alpha-D-galactopyranoside, 3-aminopropyl alpha-L-rhamnopyranosyl-(1-->4)-D-ribityl-(5-->hydrogen phosphate-->2) -alpha-D-galactopyranoside, and 3-aminopropyl D-ribityl-(5-->hydrogen phosphate-->2) -alpha-D-galactopyranosyl-(1-->3)-alpha-D-glucopyranoside. Phosphorylations were carried out using the H-phosphonate method.