Di-D-fructofuranose anhydride

Difructose anhydrides II and III were first reported by Jackson and McDonald.74 In both cases molecular weight determinations indicated a difructose anhydride molecule. Difructose anhydride III has been shown by the following procedure78 to be 1,2 2,3 -di-D-fructofuranose anhydride. 

In 1933, Schlubach and Knoop32 isolated a di-D-fructose dianhydride from Jerusalem artichoke and tentatively identified it as difructose anhydride I [a-D-Fru/-1,2 2,1 - 3-D-Fn / (5)]. Alliuminoside ( -D-fructofuranose- -D-fructofura-nose 2,6 6,2 -dianhydride) was isolated from tubers of Allium sewertzowi by Strepkov33 in 1958. Uchiyama34 has demonstrated the enzymic formation of a-D-Fru/-1,2 2,3 -(3-D-Fru/ [di-D-fructose anhydride III (6)] from inulin by a homogenate of the roots of Lycoris radiata Herbert. 

It is interesting to note that the formation of the dioxane ring stabilizes the anhydrides as to their pyranose or furanose structures, difructose anhydride I as 2,1 l,2 -di-D-fructofuranose and dihetero-levulosan as 2,1 l,2 -di-D-fructopyranose. 

Jackson and Goergen 133) and Jackson and McDonald 134) have isolated three dianhydrides of D-fructose from the nonreducing residue that remains after the removal of D-fructose from the acid hydrolyzate of inulin 135). On the basis of methylation data 136), structure (III) was assigned to difructose anhydride I. Difructose anhydride III was considered 135) to be di-D-fructofuranose l,2 2,3 -dianhydride. Wolfrom, Hilton, and Binkley 129) believe, on the basis of rotational data, that difructose anhydrides II and III are structural units differing only in the configuration of one of the asymmetric centers on the substituted dioxane ring. 

Other Anhydrides.- A laboratory scale apparatus has been designed for the pyrolysis of cellulose in large quantities to give 1,6-anhydro-)9-D-glucopyranose,and the preparation of this compound uniformly labelled with C by pyrolysis of a [U- " C] glucan has been reported. Pyrolysis of plant cell wall materials has afforded 1,5-anhydro-/9-L-arabinofuranose in up to 78% yield based on the amount of L-arabinose present in the glycan. The treatment of acetylated inulin with anhydrous HF has allowed the formation of the fructofuranose 1,2 2,1 -dianhydride (27), whereas 2,3 4,6-di-Q-isopropylidene-a-L-sorbopyranose on brief treatment under the same conditions afforded the sorbofuranose 1,2 2,1 -dianhydride (28) isolated as its crystalline hexaacetate. The... 

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