Synthesis of di- and tetrasaccharide containing 6-deoxytalose from the O-antigenic polysaccharide of B. pseudomallei strain 304b

Synthesis of the disaccharide β-d-Glup-(1→3)-6-deoxy-α-l-TalpII, and its dimer III from the O-antigenic polysaccharide of Burkholderia pseudomallei strain 304b, were achieved through assembly of suitably synthesized building blocks, 4-methoxylphenyl 6-deoxy-2,4-di-O-benzoyl-α-l-talopyranoside (7), 3-O-allyl-2,4,6-tri-O-benzoyl-α,β-d-glucopyranosyl trichloroacetimidate (8) and 2,3,4,6-tetra-O-benzoyl-α,β-d-glucopyranosyl trichloroacetimidate (11). The total yield of III from 4-methoxylphenyl 2,3-O-isopropylidene-α-l-rhamnopyranoside (1) was 18%.