Of di-D-fructose dianhydrides

Isolation of Di-D-fructose Dianhydrides from Higher Plants. 213... 

Acid Hydrolysis of Di-D-fructose Dianhydrides and Their Per-O-methyl... 

The literature in this field is confusing because of a somewhat haphazard method of nomenclature that has arisen historically. This is compounded by some mistakes in structure determination, reported in early papers, and which are occasionally quoted. The first part of this chapter deals with nomenclature and with a brief overview of early work. Subsequent sections deal with the formation and metabolism of di-D-fructose dianhydrides by micro-organisms, and the formation of dihexulose dianhydrides by protonic and thermal activation. In relation to the latter topic, recent conclusions regarding the nature of sucrose caramels are covered. Other sections deal with the effects of di-D-fructose dianhydrides upon the industrial production of sucrose and fructose, and the possible ways in which these compounds might be exploited. An overview of the topic of conformational energies and implications for product distributions is also presented. 

The biosynthesis and degradation of fructans by microbial organisms has been reviewed in detail recently.35 Additionally, a review of the production of di-D-fructose dianhydrides from inulin and levan by enzymes has been published in Japanese.36 This account is therefore limited to a general overview. 

A mechanism was proposed31 for the formation of di-D-fructose dianhydrides from inulin and fructose. It was suggested that a-D-Fru/-1,2 2,1 - 3-D-Fru/ [difructose anhydride I (5)] formed first and then isomerized via ionic intermediates to produce the remaining products. Important support for the concept of the reversibility of the isomerization was the observation that ot-D-Frup-1,2 2,1 - 3-D-Frup (4) and p-D-Frup-1,2 2,1 - 3-D-Frup produced, upon treatment with HF, the same product mixture as did D-fructose. 

VIII. Uses of Di-d-fructose Dianhydrides 1. Di-D-fructose Dianhydrides and Nutrition... 

The raw materials from which di-D-fructose dianhydrides can be obtained in appreciable yield are readily available from comparatively inexpensive agricultural feedstocks. Thus, these compounds are attractive as chiral-starting materials for chemical synthesis. Their stability to acid and heat, and their relative rigidity, because of the conformational constraints covered here, are also features that might be exploited during syntheses.119 A series of variously substituted di-D-fructose dianhydrides has been prepared,119 starting from 6,6 -dideoxy-6,6 -di-halosucroses. The properties of these and other derivatives of di-D-fructose dianhydrides are summarized in Tables XIV-XX. Two of these derivatives, 48 and 56, exhibit thermotropic liquid-crystal properties.119... 

Optical Rotations and Melting Points of Di-D-fructose Dianhydride Derivatives and Their Per-0-acetates... 

H NMR Spectra of Fructose Components of Derivatives of Per-0-acetyl Derivatives of Di-D-fructose Dianhydrides... 

Christian, T.J., Manley-Harris, M., Field, R.J., and Parker, B.A., Kinetics of formation of di-D-fructose dianhydrides during thermal treatment of inulin, J. Agric. Food Chem., 48, 1823-1837, 2000. 

Fig. 1 Chemical structures of di-D-fructose dianhydrides (1-7 and 9-14) and of a D-fructose-D-glucose mixed dianhydride (8), with indication of the preferred conformation of six-membered rings...

Kawamura M, Uchiyama T (2007) Chemistry and production of di-D-fructose dianhydrides. In Norio S, Noureddine B, Shuichi O (eds) Recent advances in fructooligosaccharides research. Research Signpost, Kerala, India, pp 273-296... 

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