The synthesis is reported of propyl 4- O-α-D-galactopyranosyl-β-D-glucopyranosiduronic acid ( 25), 4- O-[4- O-(β-D-glucopyranosyluronic acid)-β-D-glucopyranosyl]-D-glucopyranose ( 34), and 4- O-(4- O-β-D-glucopyranosyl-α-D-glucopyranosyl)-D-galactopyranose ( 38), each representing a structural element of the repeating unit of the capsular polysaccharide of Streptococcus pneumoniae type 8, [→4)-β-D-Glc pA-(1→4)-β-D-Glc p-(1→4)-α-D-Glc p-(1→4)-α-D-Gal p-(1→] n. 2,3-Di- O-benzyl-4,6- O-benzylidene-α-D-galactopyranosyl trichloroacetimidate ( 12) was coupled to allyl 2- O-acetyl-3- O-benzyl-6- O-trityl-β-D-glucopyranoside ( 7) in dichloromethane-ether, using trimethylsilyl trifluoro-methanesulfonate as a promoter, to give disaccharide derivative 20. Detritylation of 20, followed by oxidation and deprotection, afforded disaccharide propyl glycoside 25. Coupling of 2,3,4,6-tetra- O-acetyl-α-D-glucopyranosyl trichloroacetimidate ( 8) to allyl 2,3,6-tri- O-benzyl-4- O-(2,3,6-tri- O-benzyl-β-D-glucopyranosyl)-β-D-glucopyranoside ( 17) in dichloromethane, with trimethylsilyl trifluoromethanesulfonate as a promoter, resulted in trisaccharide derivative 26. Deacetylation of 26, followed by 6- O-tritylation, benzylation, detritylation, and oxidation gave a protected trisaccharide derivative ( 31), which, after deprotection, afforded 34. Coupling of allyl 2,3,6-tri- O-benzyl-β-D-galactopyranoside ( 10) to 4- O-(2,3-di- O-benzyl-4,6- O-benzylidene-β-D-glucopyranosyl)-2,3,6-tri- O-benzyl-D-glucopyranosyl trichloroacetimidate ( 19) in ether, with trimethylsilyl trifluoromethanesulfonate as a promoter, gave trisaccharide derivative 35. Deallylation of 35, followed by hydrogenolysis afforded 38.