Abstract:

D-Mannitol 1 is a convenient starting material for organic synthesis because of the homotopic relation between the upper and the lower part of the molecule. For this reason dehydration of 1 via 2-5 hydroxyl groups yields one product only, i.e. 2,5,- anhydro-D-glucitol 2. Our interest in 2 and its derivative 5 stems from a possibility of application of the latter for C-nucleoside synthesis. Acid catalyzed dehydration of 1 was performed followed by some manipulations, and permitted isolation of the 2,5- anhydro-4,6-di-O-benzyl-D-glucitol 5, together with 2,6-anhydro-1,3-di-O-benzyl-D-mannitol 7 (or 1,5- anhydro-4,6-di-O-benzyl-D-mannitol due to a symmetry of 1). A structure of 7 was confirmed by xray analysis.