Several maltose derivatives containing sulfur atom in C1 and C6 positions in maltose have been synthesized. Treatment of maltosan hexaacetate (II) with titanium tetrabromide in chloroform, followed by acetylation with mercuric acetate in acetic acid, afforded 1, 2, 3, 2', 3', 4', 6'-hepta-O-acetyl-β-maltose (III) in 41% yield. Heating of the corresponding 6-tosylate (V) with potassium thiolacetate in N, N-dimethylformamide afforded 1, 2, 3, 2', 3', 4', 6'-hepta-O-acetyl-6-S-acetyl-6-deoxy-6-thio-β-maltose (VII). Deacetylation of VII gave 6-deoxy-6-thio-maltose (IX) as a sirup which contained two products, disulfide and thiol. Starting from 6-mesylate (IV) or 6-tosylate (V), crystalline 1, 6-anhydro-2, 3, 2', 3', 4', 6'-hexa-O-acetyl-6-deoxy-6-thio-β-maltose (6-thiomaltosan hexaacetate) (XV) was synthesized by an analogous reaction sequence describing in the preparation of 6-thiolactosan hexaacetate ; S. Tejima, Carbohyd. Res., 20, 123 (1971). Deacetylation of XV afforded 1, 6-anhydro-6-deoxy-6-thio-β-maltose (6-thiomaltosan) (XIX) as amorphous powders. Acetolysisof XV gave 1, 2, 3, 2', 3', 4', 6'-hepta-O-acetyl-6-deoxy-6-thio-6-S-acetyl-α-maltose (XVIII). Reductive desulfurization of XV, followed by deacetylation, yielded 1, 5-anhydro-4-O-α-D-glucopyranosyl-6-deoxy-D-glucitol (XVII) as amorphous powders. Syntheses of several 1-thio-β-maltose derivatives have also been described.