SYNTHESIS OF NOVEL 3,3-GEM-BRANCHED-CHAIN-SUGAR DERIVED FROM D-FRACTOSE

The natural occurrence of branched-chain sugar in various antibiotics has stimulated a considerable amount of research towards their synthesis. Several branched-chain sugar derivatives have been synthesized and evaluated as anti-cancer agents. Anti-angiogenesis agents and other biological activities. In general various branched-chain sugar have been synthesized by applying Grignard reaction, Reformatsky reaction, Witting reaction, nitro methane, diazomethane, cyanohydrins synthesis , and dichloromethyl lithium , to a suitable keto sugar. Keto sugars are still used in reaction with nucleophilic species. On the other hand, un saturated sugars includes Michael addition reaction. Both class are for the direct formation of the C-C bond . Several other methaods have been proposed such as the ring opening of spirocyclopropane or the addition of dimethylcuprate on β-methyl substituted enone .