Structures of 2-Oxo-l, 3-bis phenylhydrazones

Vicinal tris(phenylhydrazones) of cyclitols, as with 2-oxo-l,3-bis(phenylhydrazones), possess two chelated-ring structures. The NMR spectra of l,2,3-tris(phenylhydrazono)cyclohexane (64), l,2,3-tris(phenylhydrazono) 

Bis- and tris-phenylhydrazones that possess keto groups exhibit hypsochromic shifts in basic media, because they readily tautomerize to enolates, which are 

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