Glycosylamines ammonia

The formation10 12 of N-acetyl-a-D-glucofuranosylamine (15) from 1,2,3,4,6-penta-O-acetyl-D-glucopyranose, and, by extension, of other N-acyl-D-glycosylamines, would start with the rapid elimination of the acetyl group on 0-1 to give 89. In this way, C-l is ready to combine with ammonia to give the intermediate 90 and, subsequently, the... 

What promises to be a valuable and time-saving method has been developed by Bayly and Bourne.22 The oligosaccharides are reacted with benzylamine, directly on the paper. Development of the A-benzyl-A-glycosylamines is then carried out, using 1-butanol-ethanol-ammonia-water mixtures. In a typical separation, the derivatives of malto-... 

A study of the Tables at the end of this review will reveal that a wide range of amines has been used to prepare compounds of the type under discussion. They include ammonia, and primary and secondary aliphatic, alicylic, and aromatic amines, as well as many heterocyclic amines. The methods used for preparing arylhydrazones of sugars (and the properties of these compounds) have many similarities with those for glycosylamines. These hydrazones have been surveyed by Percival. ... 

Glycosylamines from simple secondary amines, such as N-glycosyl piperidine, appear to behave like glycosylamines derived from primary amines and ammonia. Where, however, formation of a cationic Schiif base would involve disruption of an aromatic sextet (as with glycosyl imidazoles, pyrazoles and purines) the glycosylamines are configurationally stable. 

Owing to the presence of active methylene compounds and ammonia, the conditions of these reactions are favorable for the occurrence of an Amadori rearrangement, and, on this basis, the structures proposed by Voto6ek and Valentin have been questioned.The products could be derived either from glycosylamines or from the 1-amino-l-deoxyketoses that result from their Amadori rearrangement. 

A re-investigation of the reaction showed, in accordance with VotoCek s hypothesis, that the compounds obtained have properties (for example, color reactions, ultraviolet and infrared spectra, hydrolysis when examined chromatographically) similar to those of the /3-(glycosylamino) a, 8-un-saturated esters or ketones prepared directly from glycosylamines and i3-dicarbonyl compounds. The derivatives from L-rhamnose and ammonia with ethyl acetoacetate and with 2,4-pentanedione are, indeed, identical... 

Maltosylamine has been prepared crystalline by prolonged exposure of maltose to methanolic ammonia containing ammonium chloride, and it was shown to possess specific inhibitory activity towards sweet potato jS-amylose. Furanoid glycosylamines have been similarly prepared from 5-O-trityl-D-ribose, -D-arabinose, -D-xylose, and -2-deoxy-D-ribose and are potentially useful in the synthesis of nucleosides. ... 

The treatment of sugars in alcoholic solution (or suspension) with ammonia produces glycosylamines (glycosimines or glycose ammonias) by... 

Some developing solvents used in paper chromatography of sugars contain ammonia. With such solvents the formation of glycosylamines may occur. Such products may be identified by their reactions with ninhydrin 63). 

The glycosylamines (1-amino sugars) are easily accessible by treatment of the appropriate aldose with anhydrous methanol saturated with ammonia. The synthesis of j3-D-galactosylamine is given here, since a published method was not satisfactory. 

Some solvents are not stable in composition due to chemical interaction of the components, for example, n-butanol/acetic acid/water and ethyl ace-tate/pyridine/water. For reproducible results, these solvents should be freshly prepared for each separation. Tertiary alcohols are recommended for use with organic acids. The use of ammonia in solvents should be avoided since it sometimes gives rise to anomalous spots on the paper chromatogram due to formation of glycosylamines (26,216). 

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