Osotriazoles, sugar

These sugar osotriazoles show sharp melting points and rotations (with no mutarotation) and give promise of aiding the precise characterization of osazones. 

First of all, new (substituted) hydrazones and osazones will be described these have been characteristic derivatives in sugar chemistry for a long time, but are now, to a certain degree, replaced by the osotriazoles. The common substituted hydrazones have been reviewed, but during the past decade a great deal of work has been done in this field, not only to resolve the last remaining doubts about osazone formation, but especially in a study of the... 

The ultraviolet absorption spectra of sugar osotriazoles are characterized by a peak between 268 and 310 m/i. The spectra hardly differ... 

Later, by using a phenylosazone formazan marked in different positions, Mester and Weygand again showed that the elimination of the arylamine during sugar osotriazole formation occurs from the hydrazone residue on C-1 of the sugar residue. 

The sugar residues in osotriazoles can be readily acetylated, benzoylated (see Table II, p. 117), or p-toluenesulfonated. Further, as previously stated, osotriazoles can be oxidized with sodium periodate or red lead to give 4-formyl-2-phenyl-l,2,3-triazole (3), or with 20% nitric acid, aqueous potassium permanganate, or ceric sulfate to give 2-phenyl-l,2,3-triazole-4-carboxylic acid (5). 

In view of their sharply defined physical constants, sugar osotriazoles have been used for the identification of sugars and their osazones. It has now become customary to confirm the identity of sugar osazones by comparing their phenylosotriazoles. ... 

The osazones of the sugars are converted to osotriazoles when they are heated in aqueous copper sulfate solution 239). These derivatives offer considerable promise for the identification of the sugars and as confirmatory... 

Osotriazoles of diketones previously had been described by von Pech-mann 2 0) who obtained them by the oxidation of the corresponding di-hydrazones. The corresponding osotriazoles of the sugars are formed directly by the action of copper sulfate. The formation of the phenyl-D-glucoso-triazole (II) from glucose phenylosazone (I) is illustrated. Its structure is demonstrated by oxidation with periodic acid to the 2-phenyl-4-formyl-osotriazole (III) which is identical with the product obtained previously by von Pechmann from mono-0-acetyldinitrosoacetone phenylhydrazone (IV). 

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