Starting 1,2,3,4-tetra-O-acetyl-6-O-tosyl-β-D-glucopyranose (3) was converted into 2,3,4-tri-O-acetyl-1-thio-6-O-tosyl-β-D-glucopyranose (6) via intermediate glycosyl bromide 4 and S-thiouronium salt 5. Treatment of compound 6 with sodium methoxide gave 1,6-anhydro-1-thio-β-D-glucopyranose (thiolevoglucosan 2a). The isomeric sulfoxides 7 and 8 were prepared by selective oxidation of thiolevoglucosan 2a with hydrogen peroxide or 3-chloroperoxybenzoic acid. The structure of new compounds was confirmed by 1H and 13C NMR spectroscopy or by X-ray analysis; magnetic anisotropy of the sulfinyl and sulfonyl group has been discussed.