The syntheses of several α-linked thioglycosidic disaccharides are described, including thiokojibiose octaacetate (1), thionigerose (2), and thioisomaltose (3). The title compounds were synthesized by coupling 2,3,4,6-tetra-O-acetyl-1-S-acetyl-1-thio-α-d-glucopyranose (4) with either 1,3,4,6-tetra-O-acetyl-2-O-trifluoromethylsulfonyl-β-d-mannopyranose (7), 1,2:5,6-di-O-isopropylidene-3-O-trifluoromethylsulfonyl-α-d-allofuranose (15), or methyl 2,3,4-tri-O-acetyl-6-deoxy-6-iodo-α-d-glucopyranoside (17), respectively. Thiokojibiose octaacetate in turn was converted to 3,4,6-tri-O-acetyl-2-S-(2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl)-2-thio-α-d-glucopyranosyl bromide (9), which was used to obtain several related disaccharides and one trisaccharide. All of the compounds, including thiomaltose and thiotrehalose, which were resynthesized by known methods, were tested for their anti-HIV activity in either CEM or MT-2 cells. Anti-HIV activity was noted only with thiokojibiose octaacetate and its 1-thio analogue (14), which had IC50 values of 51 and 48 μg/mL in CEM cells, respectively. © 1994.