A convenient synthesis of d-idose

Addition of nitromethane to d-xylose leads to the formation of two epimeric deoxynitroalditols, namely 1-deoxy-1-nitro-d-iditol and 6-deoxy-6-nitro-l-glucitol. Conversion of the former, obtainable in good yield by direct crystallisation, by a modified Nef reaction in an argon atmosphere afforded 68% of d-idose, which may readily be converted into 1,6-anhydro-β-d-idopyranose (“d-idosan”).