Fructofuranose 2,6-anhydro

Anhydro-a-D-fructofuranose P-D-fructopyranose l,2 2,l -dianhydride (55) 6-Deoxy-6-isothiocyanato-a-D-fructofuranose P-D-fructopyranose 1,2 2,1 -dianhydride (56) 6-Deoxy-6-iodo-a-D-fructofuranose 6-deoxy-6-iodo-p-D-fructofuranose 1,2 2,1 -dianhydride (57) 6-Chloro-6-deoxy-a-D-fructofuTanose 6-chloro-6-deoxy-P-D-fructofuranose 1,2 2,1 -dianhydride (58) 6-S-Heptyl-6-thio-a-D-fruclofuranose 6-S-heptyl-6-thio-p-D-fructofuranose 1,2 2,1 -dianhydride (59) 6-Azido-6-deoxy-a-D-fructofuranose 6-azido-6-deoxy-P-D-fructofuranose 1,2 2,l -dianhydride (60) 6-Amino-6-deoxy-a-D-fructofuranose 6-amino-6-deoxy-p-D-fructofuranose 1,2 2,1 -dianhydride (61) 6-Acetamido-6-deoxy-[Pg.260]

Anhydro-a-D-fructofuranose 6-deoxy-6-iodo-p-D-fructofuranose 1,2 2,l -dianhydride (63)... 

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... 

O-isopropylidene-jS-D-fructopyranose via the 1-O-tosyl- or 1-deoxy-l-iodo derivatives.265 Related 1,2-anhydro-a- and /J-D-fructofuranose and... 

Thio-D-fructofuranose (88) was prepared from 5-(9-tosyl-l,3-(9-isopropylidcnc-o -L-sorbopyranose (87) by the standard sequence of reactions shown in Scheme 26. The H and C NMR spectra of 88 in aqueous solution show only tlie signals of the furanose a and p anomers in the ratio of 11 89, whereas tlie NMR spectra of D-fructose in D2O show the presence of the -pyranose, -furanose, a-furanose, and a-pyranose in the ratio of 6 3 1 trace, respectively. Partial hydrolysis or methanolysis of 90, prepared from 1,6-di-O-tosyl-D-fructofuranose (89), gave 3,6-anhydro-l-deoxy-6-thio-D-oraZ)W7o (or D-yv/o)-hexulose (91). Nucleophilic attack of the ring sulfur atom on C-3... 

Tri-O -acetyl-2,6-anhydro-p-D-fructofuranose, A-603 i-0 -acetyl-3,6-anliydro-D-fructose, A-607... 

Anhydrofructose D-form, A-607 l,2-Anhydro-3,4,5-tri-0-benzyl-p-D-fructopyranose, A-604 6-Azido-6-deoxyfructose D-form, A-901 6-Azido-3,4-di-0-benzyl-6-deoxy-p-D-fructofuranose, A-901... 

The anhydrodisaccharides a-D-fructofuranose-P-D-fructopyranose 1,2 2,1 -dianhydride and a-D-fructofiiranose-P-D-fructofiiranose l,2 2,r-dianhydride have been identified in the ethanol-soluble products from the thermolysis of sucrose. These same products, along with di-P-D-fructofuranose-l,2 2,r-dianhydride, were found in caramelized sucrose. Dissolution of sucrose in anhydrous HF afforded a complex mixture of difructose dianhydrides and their glucosylated derivatives as well as oligosaccharides up to dp 14. a-D-Fructofuranose-P-D-fiructopyranose l,2 2,r-dianhydride was the main component in the mixture, either free or glucosylated at various positions. The reaction of some disacdiarides with anhydrous HF has afibrded some dimeric dianhydrides. Palatinose, leucrose and maltulose gave, respectively, the dianhydrides 25, 26 and 27. a-D-Fructofuranose-P-D-fmctofuranose-l,2 2,r-dianhydride has been converted into the bis-3,6-anhydro-derivative, which,... 

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. 

Synthesis of Monosaccharide Glycosides.- A review with 168 references has appeared (in Japanese) of recent developments in the synthesis of 0 -glycosides. The acid-catalyzed formation of D-fructosides and 2-thio-D-fructosldes in DMSO is believed to proceed by way of the cyclic carbonlum ions, and furanoslde-pyranoside isomerization by way of the bicyclic 2,6-anhydro-3-D-fructofuranose... 

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... 

An efficient preparation of methyl a-L-tagatopyranoside (13) from 1,5-anhydro-D-galactitol (12) in which C-6 of the starting material became C-1 of the product is outlined in Scheme 6. The selectively 1,3,4-protected fructofuranose derivative (15) is readily available by cleavage of the glycosidic bond of the perbenzylated sucrose silyl ether (14) with concomitant loss of the silyl group, by use of [4- ],[6- -labelled glucose is referred to in Part 5... 

The anomeric configurations in a-D-fructofuranose g-D-fructo-furanose 2, 1 2,3 -dlanhydrlde, a product formed in high yield by the action of a D-fructotransferase on Inulln, have been determined from its C-n.m.r. spectrum.A H-n.m.r. study on tosylated derivatives of 1,6-anhydro-g-D-glucopyranose is mentioned in Chapter 20. 

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