Osazones, defined

Glucose and fructose (and also mannose) form the same osazone. The osazones are usually yellow, well-defined crystalline compounds and are sparingly soluble in cold water. The characteristic crystalline forms of the osazones of the commonly occurring sugars, when examined under the microscope, may be employed for their identification (Fig. 9.1) the melting or decomposition... 

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. ... 

OSes which react with Fehling s solution. They give a precipitate of Cu oxide (cuprous oxide) due to their reducing power. Let s also recall the formation of osazones for the identification of oses. Oses react with phenylhydrazine in well-defined conditions to yield crystallized yellow phenylosazones poorly soluble in... 

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