Dinitrogen tetroxide oximes

The dinitromethane derivatives 135 and 136 were obtained by nitration of oximes of monoacyl furazans and furoxans with dinitrogen tetroxide [36G819, 37G518, 63T(S)143] or nitric acid (37G388, 97MI11, 97ROC1760) (Scheme 79). 

The Ponzio reaction provides a useful route to gem-dinitro compounds and involves treating oximes with a solution of nitrogen dioxide or its dimer in diethyl ether or a chlorinated solvent. The Ponzio reaction works best for aromatic oximes where the synthesis of many substituted aryldinitromethanes have been reported. Compound (56), an isomer of TNT, is formed from the reaction of dinitrogen tetroxide with the oxime of benzaldehyde (55) followed by mononitration of the aromatic ring with mixed acid. Yields are usually much lower for aliphatic aldoximes and ketoximes. " The parent carbonyl compound of the oxime is usually the major by-product in these reactions. 

The oxidation of oximes by lead(IV) acetate, chlorine and other oxidants results in the formation of a-substituted nitroso compounds R R C(X)NO by attack of the oxidant at carbon. This is also the reaction commonly observ with dinitrogen tetroxide (the Ponzio reaction), the products being gem-... 

Schmitz s compound reacts with dinitrogen tetroxide by transformation of the oxime groups into 1,1-dinitroethyl groups18 (cf. Houben-Weyl, Vol. E14b/1, p 395). 

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