Glycosylamines methylation

Early evidence that the open-chain formula is, in itself, inadequate to explain the behavior of the glycosylamines emerged from the methylation experiments of Irvine and his coworkers." iV-Phenyl-D-glucosylamine was methylated to afford a crystalline tetramethyl ether which was hydrolyzed by acid to 2,3,4,6-tetra-O-methyl-D-glucose. Condensation of the latter compound with aniline afforded the original ether, which consequently must be 2,3,4,6-tetra-O-methyl-iV-phenyl-D-glucosylamine. 

One important use of glycosylamines, for the characterization of methyl ethers of sugars obtained during structural studies on polysaccharides, has already been mentioned (see p. 110). 

The first observation on the reactions of glycosylamines with 3-dicarbonyl compounds is due to Elson and Morgan, who found that D-glucosylamine and 2,4-pentanedione, when heated in slightly alkaline solution, give a positive Ehrlich pyrrole test. They considered that 3-acetyl-2-methyl-4-(D-ara6wo-tetrahydroxybutyl)pyrrole (20) was formed and was responsible for the color reaction. 

In order to obtain strong, molecular-ion peaks, the use of N-phenyl-glycosylamines ( anilides ) or phenylosazones has been recommended, in addition to the 3-methyl-l-naphthyl and 1-phenylflavazole derivatives mentioned in Section XXV,1 (see p. 37). Diols are possible products of the periodate degradation of polysaccharides, and the mass spectra of their cyclic boronic esters have been examined. 

Differences were observed in the e.s.r. spectra of the epimeric methyl 2,3,6-tri-Q-benzoyl-4-deoxy-4-hydrojq lamino-o-D-gluco- and -galacto-pyranosides. A one step synthesis of water-soluble spin-labelled glycosylamine derivatives involved condensation of amino-substituted N-oxides with free sugars (see Chapter 10) e. r. spectra were recorded. ... 

The glucose heptamer 22, which has been synthesized, is a phytoalexin elicitor of soya beans, and compound 23, which is the heptasaccharide moiety of ganglioside BGMj has been prepared as the methyl ester of the neuraminic acid moiety." Compound 24 has been prepared and in the form of its glycosylamine linked to a pentapeptide to give a product which represents a unit of ovalbumin." ... 

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