DIFRUCTOSE DIANHYDRIDES FROM SUCROSE AND FRUCTOOLIGOSACCHARIDES AND THEIR USE AS BUILDING-BLOCKS FOR THE PREPARATION OF AMPHIPHILES, LIQUID-CRYSTALS, AND POLYMERS

Controlled selective protonic activation of the fructosyl moiety in sucrose and fructo-oligosaccharides, with pyridinium poly(hydrogen fluoride) at 20 degrees C, yielded either the kinetic product alpha-D-fructofuranose beta-D-fructofuranose 1,2':2,1'-dianhydride (1), or its thermodynamically more stable isomer alpha-D-fructofuranose beta-D-fructopyranose 1,2':2,1'-dianhydride (2), depending on the hydrogen fluoride-pyridine ratio. A similar reaction was performed with 6,6'-dichloro-6,6'-dideoxysucrose, or 6,6'-dideoxy-6,6'-diiodosucrose, using a slightly higher ratio of HF, resulting in the corresponding 6-deoxy-6-halo-alpha-D-fructofuranose 6'-deoxy-6'-halo-beta-D-fructofuranose 1,2':2,1'-dianhydride derivatives. Both 6,6'-dihalides were converted, upon action of the appropriate nucleophile, into the difructofuranose dianhydride derivatives bearing the 6,6'-di-S-heptyl-6,6'-dithio, 6,6'-diazido-6,6'-dideoxy and then 6,6'-diamino-6,6'-dideoxy functionalities, 6-Chloro-6-deoxy and 6-deoxy-6-iodo derivatives of 2 were also prepared by direct halogenation, and further converted into the 6-S-heptyl-6-thio, 6-azido-6-deoxy and then 6-amino-6-deoxy derivatives of 2. Reaction of chloromethyloxirane with 1 or 2 yielded hydrophilic polymers. The 6,6'-di-S-heptyl-6,6'-dithio derivative of 1 displayed liquid crystal properties. The 6,6'-dideoxy-6,6'-diiodosucrose precursor was prepared by the reaction of Garegg's iodine-imidazole-triphenylphosphine reagent with sucrose in N,N-dimethylformamide solution.