Galactose pentaacetate

By contrast, the D-glucose isothiocyanate derivative 33 was synthesized from d-galactose pentaacetate 27 (Scheme 7) 51. Reaction of 27 with benzyl alcohol followed... 

Anomeric ediyl hemiacetals of the methyl ester of aldehydo-D-galacturonic acid tetraacetate were prepared by Dimler and Link. In chloroform, these isomers mutarotated to an intermediate value over a period of several hours, and the mutarotation was complex. Solvent-free oldehydo-D-galactose pentaacetate was obtained in crystalline form, and did not show mutarotation in 1,1,2,2-tetrachloro-ethane. " In the presence of water, the corresponding crystalline aldehydrols of aZde/tydo-D-galactose pentaacetate and aldehydo-T>-mannose pentaacetate were obtained. 

C16H22011 b-D-galactose pentaacetate 4163-60-4 25.00 1.3200 2 29814 C16H36Br3N tetra-n-butylammonium tribromide 38932-80-8 25.00 1.3364 2... 

Manganese is not the only metal capable of effecting carbon monoxide insertion reactions. In 1988, Chatani et al. [166] demonstrated the utility of cobalt in the generation of C-glycosides. Specific examples, shown in Scheme 7.54, involve the conversion of glucose and galactose pentaacetates to... 

Hemi-acetals of Aldehydo-Galactose Pentaacetate and Their Optical Properties, M. L. Wolfrom and William M. Morgan, J. Amer. Chem. Soc., 54, 3390-3393 (1932). 

The acyloxonium rearrangement provides a good preparative access to D-talose from D-galactose. Thus, tetra-0-acetyl-/3-D-galactopy-ranosyl chloride (90) is treated with antimony pentachloride to give the mixture of salts 91 and 92, which is hydrolyzed and the mixture of products acetylated. Penta-O-acetyl-a-D-talopyranose, which is present as the pure a-D anomer, crystallizes out from the mixture, whereas the D-galactose pentaacetate does not. The latter exists as a difficultly crystallizable, a,/3 mixture, because hydrolysis of 91 and acetylation of the product leads to an anomeric mixture. 

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