Steric and electronic effects in the formation of dihexulose dianhydrides. Reaction of racemic sorbose in anhydrous hydrogen fluoride and a facile synthesis of D-sorbose

Article abstract of DOI:10.1016/0008-6215(92)84157-N

Treatment of DL-sorbose with anhydrous hydrogen fluoride gave a high yield of α-D-sorbopyranose α-L-sorbopyranose 1,2':2,1'-dianhydride.Similarly, a mixture of D-fructose and D-sorbose gave a good yield of β-D-fructopyranose α-D-sorbopyranose 1,2';2,1'-dianhydride.The formation of these products, compared to the more complicated mixtures of compounds obtained by treatment of L-sorbose or D-fructose with hydrogen fluoride, is discussed in terms of conformations, and steric and electronic factors.