alpha,alpha-Trehalose 2-sulfate, the core carbohydrate of sulfatides of Mycobacterium tuberculosis, and the 3-sulfate isomer were synthesized by sulfation of 4,6:4',6'-di-O-benzylidene-alpha,alpha-trehalose with pyridine-sulfur trioxide complex to give the 2- and 3-sulfates, which were separated by column chromatography. The ammonium 2-sulfate salt wa was identical with the natural product obtained from the principal sulfatide (SL-I) of M. tuberculosis.