Novel 4-thiogalactofuranosyl-containing disaccharides with nitrogen in the interglycosidic linkage

The syntheses of three novel disaccharides containing a 4-thiogalactofuranosyl residue as the non-reducing unit and a nitrogen in the interglycosidic linkage are described. Acid-catalyzed condensation reactions of 4-thio-α/β-d-galactofuranose with either methyl 3-amino-3-deoxy-α-d-mannopyranoside, methyl 2-amino-2-deoxy-α-d-mannopyranoside, or methyl 2-acetamido-6-amino-2,6-dideoxy-β-d-glucopyranoside gave methyl 3-amino-3-deoxy-3-N-(4-thio-α/β-d-galactofuranosyl)-α-d-mannopyranoside, methyl 2-amino-2-deoxy-2-N-(4-thio-α/β-d-galactofuranosyl)-α-d-mannopyranoside, or methyl 2-acetamido-6-amino-2,6-dideoxy-6-N-(4-thio-α/β-d-galactofuranosyl)-β-d-glucopyranoside.