ACETAL AND ESTER PROTECTING-GROUPS IN THE HYDROGEN FLUORIDE-CATALYSED SYNTHESIS OF D-FRUCTOSE AND L-SORBOSE DIFURANOSE DIANHYDRIDES

Article abstract of DOI:10.1016/0008-6215(88)85101-2

Treatment of acetylated inulin with anhydrous hydrogen fluoride under mild conditions gave a good yield of tri-O-acetyl-α-D-fructopyranose tri-O-acetyl-β-D-fructofuranose 1,2':2,1'-dianhydride together with smaller amounts of the corresponding β,β-anomer.When 2,3:4,6-di-O-isopropylidene-α-L-sorbofuranose was treated with hydrogen fluoride under similar conditions, with a short reaction time, α-L-sorbofuranose β-L-sorbofuranose 1,2':2,1'-dianhydride was obtained.A longer reaction time led to a rearranged product, di-α-L-sorbofuranose 2,1':3,2'-dianhydride.