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(27), which are structural elements of the capsular polysaccharides of Streptococcuspneumoniae types 6A and6A X = 3,6B X = 4}, have been synthesised. Ethyl 3-O-allyl-2,4,6-&i-0-benzyl-l-thio$-D-glucopyranoside (3) was coupled with benzyl2,4-di-0-benzyl-a-L-rhamnopyranoside (4), and subsequent deallylation (-14) and debenzylation gave 15. Condensation of 14 with ethyl 2,3,4,6-tetra-O-benzyl-I-thio-B-D-galactopyranoside (2) followed by debenzylation gave 17. Acetylation of I7 followed by removal of AcO-I, conversion into the imidate, coupling with 1,2,4,5-tetra-0-benzyl-D-ribitol (ll), deacetylation, anddebenzylation gave23. Coupling of the imidate with l-0-allyloxycarbonyL2,3,Mri-0-benzyl-Dribitol(l2) followed by deallyloxycarbonylation, deacetylation, and debenzylation yielded 27.