PROCESS FOR PREPARING HEXITOLS CONTAINING FREE CARBOXYL GROUP

Hexitols of the general formula (wherein the hexitol skeleton corresponds to dulcitol, mannitol or iditol, R@ represents a halogen atom, R represents a hydroxy group, or R and R together form an oxygen atom; R represents a free carboxy containing saturated or unsaturated alkylcarbonyl group with 4 to 10 carbon atoms, a free carboxy containing arylcarbonyl group with 8 to 12 carbon atoms or a free carboxy containing satiurated or unsaturated aralkylcarbonyl group with 9 to 11 carbon atoms) and Rs@ represents a hydrogen atom, a free carboxy containing saturated or unsaturated alkylcarbonyl group with 4 to 10 carbon atoms, a saturated or unsaturated C2-10 alkylcarbonyl group, an alkoxycarbonyl containing saturated or unsaturated alkylcarbonyl group with 4 to 10 carbon atoms, a saturated or unsaturated C8-10 aralkylcarbonyl group, a free carboxy containing arylcarbonyl group with 8 to 12 carbon atoms or a free carboxy containing saturated or unsaturated aralkylcarbonyl group with 9 to 11 carbon atoms) and salts thereof possess tumour inhibiting activity. The hexitols of the present invention are prepared by hydrogenation of a corresponding benzyloxycarbonyl containing 1,2-5,6-dianhydrohexitol, reaction of 1,2-5,6-dianhydrohexitol with a dicarboxylic acid anhydride and halogenation of a corresponding 1,2-5,6-dianhydrohexitol.