Heptuloses 2,7-anhydro

On deamination, l-amino-2,6-anhydro-l-deoxy-D-giycero-D-ga-Zacfo-heptitol (84) gave the corresponding anhydroheptitol (85) in 58% yield, plus the l-deoxy-2-heptulose 86, isolated in syrupy (17%) and crystalline (8%) forms.165 The rearrangement leading to the latter... 

Substitution was also the major reaction in the deamination of l-amino-2,6-anhydro-l-deoxy-D-allitol 67and l-amino-2,6-anhydro-l,7-dideoxy-L-g(i/cero-L-ga(acfo-heptitol.168 The rearrangement product, a l,6-dideoxy-2-heptulose, was also isolated from the latter amine, the ratio of substitution to rearrangement being 1.6 1. 

For aldohexoses, OH-1, OH-2, and OH-6 seem to be particularly reactive [399,400]. Nevertheless, the initial product of the treatment of D-a/tro-3-heptulose (coriose) with chlorotrimethylsilane in pyridine is claimed to have a free hemiacetal hydroxyl group [401]. 1,6-Anhydro-P-D-glucopyranose yielded 87% of the 2,4-disilyl ether [402],... 

L. C. Stewart, E. Zissis, and N. K. Richtmyer, The formation of 2,7-anhydro-a-L-gn/ncto-heptulofuranose and 2,7-anhydro-Zi-L-grz/acio-heptulopyranose by the action of acid on L-ga/acto-heptulose (perseulose), J. Org. Chem., 28 (1963) 1842-1844. 

The dehydration of hexose, heptose, and octose phenylosazones in methanolic sulphuric acid has been studied. Each osazone gave rise to two 3,6-anhydrides epimeric at C-3 except 7-deoxy-D-wa no-heptulose phenylosazone which afforded only the 3,6-anhydro-7-deoxy-L- M/o-heptulose phenylosazone with... 

Trityl, 5-Ac 5-0-Acetyl-2,6-anhydro-3-deoxy-7-0-trityl-D-2n abino-4-heptulose [54594-51-3]... 

Deoxy, 5,7-0-benzylidene 2,6-Anhydro-5,7-0-benzylidene-l,3-dideoxy-D-SLtahi-no-4-heptulose [66149-65-3]... 

Amino-2,7-anhydro-4-deoxy-o//o -heptulose, A-134 4-Amino-2,7-anhydro-4-deoxy-o//ro -h tulose. A-135... 

Anhydro-1,3,4,5-tetra- 0 -benzoyl- p-D-g/wco -2-heptulopyranose, H-59 1 - O -Benzyl-D-gw/o -heptulose, H-60 l-Deoxy-2,7-anhydroaltroheptulose T>-form, D-38 l-T>toxy-galacto -heptopyranos-6-ulose a-D-/orw ... 

Heptulose p-L-Pyranose-/orm 2,7-Anhydro, H-60 -2-Heptulose D-form, H-55 alio -2-Heptulose L-form, H-55 fl/fro-2-Heptulose D-form, H-56 fl/fro-3-Heptulose D-form, H-57... 

Amino-2,7-anhydro-4-deoxy-a//o-heptulose p-D-Pyranose-/< rm, A-134 4-Amino-2,7-anhydro-4-deoxy-a/iro -heptulose p-D- ranose-/< rm, A-135 4-Amino-2,7-anhydro-4-deoxy-gw/o-heptulose p-D-P anose-/< rm, A-136... 

Ketoheptoses (heptuloses) and their anhydro derivatives, the heptulo-sans, are recognized by using 0.5% w/v orcinol and 15% w/v trichloroacetic acid in water-saturated butanol (158). On heating at 105 for 20 minutes these sugars show up as characteristic blue spots and ketohexoses as yellow spots (33,191). 

A reinvestlgatlon of the dehydration of D-galacto-heptulose phenylosazone showed the product to be a mixture of the 3,7-anhydrides (33) with a pyranosyl ring, and not the furanosyl 3>6-anhydro-counterparts as previously claimed (Vol.l4, p.88) further data on such dehydration reactions is detailed in Section 6. Further details on the dehydratlve cyclization of the phenylosazones of L-lyxo- and L-xylo-hexulose and 7-deoxy-L-manno-heptulose have been reported (Vol.liJ, p.88 V0I.15, p.ll2). ° ... 

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