SYNTHESIS OF PROTECTED FRAGMENTS OF THE CAPSULAR POLYSACCHARIDE FROM STREPTOCOCCUS-PNEUMONIAE TYPE-8

Oxidation of acetates of ally] and 2-(benzyloxycarbonylamino)ethyl beta-cellobiosides (with OH-4' and OH-6' unprotected) with the Jones reagent followed by esterification (with diazomethane or phenyldiazomethane) gave corresponding uronates with OH-4' unsubstituted. Condensation of these glycosyl acceptors and benzylated derivatives of D-galactose or 4-O-(alpha-D-glucopyranosyl)-D-galactose led to the protected tri- and tetrasaccharide fragments of the capsular polysaccharide from Streptococcus pneumoniae type 8.