0-d-glucose pentaacetate

Penta-O-acetyl-a/de/iycfo-D-glucose 2,4-Di-0-acetyl-6-0-trityl-D-glucopyranose or a/dehydo-D-glucose pentaacetate... 

Although the above condensations definitely failed to yield sucrose octaacetate, Irvine and his collaborators showed that they did produce, in addition to uncrystallized products, some D-glucose pentaacetate, some... 

Also, the Ai peak (m/e 331) in the spectrum of a-D-glucose pentaacetate (12) is more intense than in that of the 0-d anomer (9). 

A classical selective reaction, described by Fischer and Armstrong,166 in which 6-bromo-6-deoxy-2,3,4-tri-0-acetyl-a-D-glucopyranosyl bromide (LXXXIX) is obtained from 0-D-glucose pentaacetate and liquid hydrogen bromide, has had application in the synthesis of 6-substituted D-glucose derivatives. The action of liquid hydrogen chloride on D-glu-cose has been studied by Hess, Strieker and Rutkowski,168 who have postulated a 1,1-chlorohydrin (XC) as an initial intermediate of the reaction. 

To obtain the ethylene oxide type compound, /3-D-glucose pentaacetate was treated with an excess of phosphorus pentachloride to give 2-tri-chloroacetyl-3,4,6-triacetyl-/3-D-glucopyranosyl chloride.63,63a The tri-chloroacetyl group was removed by treatment with a dry ethereal solution of ammonia at 0°. From the product the anhydride may be obtained by... 

In all of these processes, it is not clear whether the aluminum chloride, the phosphorus pentachloride, or both are the primary chlorinating agents. While phosphorus pentachloride alone in chloroform has been reported9 to produce tetraacetyl-a-D-fructosyl chloride from /3-D-fructose pentaacetate, its action on /3-D-glucose pentaacetate in the absence of... 

FRACTION OF THEORETICAL QUANTITY OF CATALYST Fig. 1. Product Yields as a Function of Catalyst Quantity in the Glucosylation of Benzene with 0-D-Glucose Pentaacetate. 

Niemann and Hays later showed that the oxidation of one mole of iV-acetyl-D-glucosylamine by lead tetraacetate involves the slow consumption of slightly more than two moles of oxidant, so confirming the result of periodate oxidation. Hockett and Chandler prepared an isomeric N-acetyl-D-glucosylamine, also cyclic since it gives a tetraacetate, by the action of 29 % aqueous ammonia on aldehydo-D-glucose pentaacetate or on hexa-0-acetyl- a -D-glucoheptonic nitrile. The oxidation of this isomer produced formaldehyde (isolated as its 2,4-dinitrophenylhydrazone), but... 

C16H22011 alpha-D-glucose pentaacetate 604-68-2 25.00 1.3200 2 29806 C16H35N02 ammonium palmitate 593-26-0 25.00 0.8879 2... 

C16H22011 beta-D-glucose pentaacetate 604-69-3 20.00 1.2740 1 29812 C16H36BrN tetrabutylammonium bromide 1643-19-2 25.00 1.0039 2... 

Dickey and Wolfrom separated a cellulose acetolyzate into a polymer-homologous series of crystalline sugar acetates complete from a-D-glucose pentaacetate through a-cellohexaose eicosaacetate by the application of chromatographic procedures. 

I) Preparation of -cf-Glucose Pentaacetate. When glucose is acetylated in presence of sodium acetate the i8-isomeric pentaacetate forms. The procedure is similar to the preparation of the a-isomer. Add 1 g of anhydrous sodium acetate to 10 ml of acetic anhydride, and heat in the water bath for five minutes. Add 1 g of powdered glucose. Heat for one hour, pour into cold water, and proceed as in section (H). The yield is about 3-4 g. If desired, the crystals are purified by recrystallization from methanol. Pure /3-d-glucose pentaacetate melts at 132°. 

Because of the unusual properties of acyclic forms, certain authors prefer to underline this situation. Compound 4.16 would be called 2,3,4,5,6-penta-O-acetyl-aldehydo-D-gluco-he ose or, more briefly, aWe/iyt/o-D-glucose-pentaacetate. 

Acetolysis of benzylidene acetals does not permit the isolation of the intermediate acetoxybenzyl ethers, presumably because of their instability. The corresponding peracetates are formed. For example, 2,5-di-O-benzoyl-1,3 4,6-di-O-benzylidenegalactitol (9) gave 1,3,4,6-tetra-O-acetyl-2,5-di-O-benzoylgalactitol (10). Similarly, 4,6-0-benzylidene-D-glucose gave D-glucose pentaacetate. ... 

He isolated a product, from the reaction of oWe/it/do-D-glucose pentaacetate with phenylhydrazine, which posed a problem in structure not solved until the technique of nuclear magnetic resonance became available, thirty years later. 

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