A convenient synthesis of sulfated and sialyl oligosaccharides as potential ligands for CD22 adhesion protein

Stereoselective syntheses of 6-OSO₃Na-Gal-β-(1→3)-GalNAc-α-OR (10), 6-OSO₃Na-Gal-β-(1→3)-6-OSO₃Na-GalNAc- α-OR (11), 3-OSO₃Na-Gal-β-(1→3)GalNAc-α-OR (13), 6-OSO₃Na-Gal-β-(1→3) [NeuAc-α-(2→6)]-GalNAc-α-OR (15), Gal-β-(1→3) [NeuAc-α-(2→6)]-GlcNAc-β-OR (18) and 6-OSO₃Na-Gal-β-(1→3) [NeuAc-α-(2→6)]-GlcNAc-β-OR (19) were accomplished through utilization of two key glycosyl donors, namely, 2,3,4-tri-O-benzoyl-6-O-bromoacetyl-α-d-galactopyranosyl bromide (3) and 2,4,6-tri-O-acetyl-3-O-chloroacetyl-α-d-galactopyranosyl bromide (4). The synthesized compounds were evaluated as ligands for CD22 adhesion protein. Synthesis of 6-O-SO₃NaGal-β-(1→3)-GalNAc-α-OR (10), 6-O-SO₃NaGal-β-(1→3)-6-O-SO₃NaGalNAc- α-OR (11), 3-O-SO₃NaGal-β-(1→3)GalNAc-α-OR (13), 6-O-SO₃NaGal-β-(1→3) NeuAc-α-(2→6) -GalNAc-α-OR (15), Gal-β-(1→3) NeuAc-α- (2→6) -GlcNAc-β-OR (18) and 6-O-SO₃NaGal-β-(1→3) NeuAc-α-(2→6) -GlcNAc-β-OR (19) were accomplished.