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. 

Difructose anhydride I was first prepared by Jackson and Goergen.18-70 These authors found a molecular weight of 307 for the anhydride and 574 for the acetate, values which indicate its difructose anhydride composition. Almost simultaneously, Irvine and Stevenson71 prepared the acetate of what they believed to be an anhydrofructose by the action of concentrated nitric acid on inulin acetate. This anhydride was later shown72 to be identical with the difructose anhydride I of Jackson and Goergen. Hexamethyldifructose anhydride I waB hydrolyzed by Haworth and Straight7 and the trimethyl-D-fructose that was formed was identified as 3,4,6-trimethyl-D-fructofuranose by quantitative conversion... 

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. 

Difructose anhydride II reacts with one mole of per-iodic acid. Hydrolysis of its methyl derivative indicates that two different trimethyl-D-fructoses are formed whose combined specific rotations in water amount to between + 20° and + 30°. If we assume that this anhydride, like the other two derived from inulin, is made up of D-fructofuranoses, the facts that have been mentioned allow only three possible structures for this anhydride. 

Anhydrides of ketoses have not been tested for polymerizability, but two monomeric anhydrides of D-fructose have been reported, namely, 2,3-anhydro-l,4,6-tri-0-nitro-D-fructofuranose71 and 2,6-anhy-dro-l-O-methyl-D-fructofuranose.72 The structures of both suggest that they have sufficient strain to be of interest. The first is the product of a... 

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. 

It was not until a quarter of a century later that an authentic chemical synthesis was accomplished by Lemieux and Huber 3), They synthesized sucrose by reacting 3,4,6-tri-O-acetyl-l, 2-anhydro-a-D-glucopyranose with 1,3,4,6-tetra-O-acetyl-D-fructofuranose in a sealed tube at 100 for 104 hours. Chromatographic separation of the products of the synthesis gave a 5.5 % yield of sucrose octaacetate. Lemieux also synthesized octa-acetyl-jS-D-maltose 99) by treatment of the same anhydride with 1,2,3,6-tetra-O-acetyl-jS-D-glucose at 120° for 13 hours. 

Ketoses do not form monomeric anhydrides, but intermolecular reactions yield tricyclic compounds. Heating of D-fructose (and also heating of saccharose or inulin) gives rise to various dianhydrides of the corresponding furanoses and pyranoses. Examples of these intermolecular anhydrides formed from fructose are the 1,2 T,2-dianhydride of a-D-fructofuranose with a-D-fructofuranose (4-193) and l,2 l, 2-dianhydride of a-D-fructopyranose with P-D-fructopyranose (4-194). Anhydrides are also formed by dehydration of disaccharides and sugar alcohols. 

Sucrose was first chemically synthesized using Brigl s anhydride and 1,3,4,6-tetra-O-acetyl-P-D-fructofuranose (the latter prepared by reacting inulin triacetate with HBr in glacial acetic acid [83] (reaction 4.69). 

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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