Conversion of oximes and hydrazones into the carbonyl compounds using dinitrogen tetroxide

Abstract

A new reaction of oximes and hydrazone derivatives using dinitrogen tetroxide under mild condition was found. The reaction of oximes and hydrazone derivatives with dinitrogen tetroxide in dry acetonitrile or tetrahydrofuran gave the corresponding carbonyl compounds respectively. Dinitrogen tetroxide has been known to be self-ionized to $NO^+$ and $NO^-_3$ ion at low temperature in aprotic solvent. Dinitrogen tetroxide is the powerful nitrosating reagent at low temperature in acetonitrile or tetrahydrofuran. The reaction appears to proceed via the formation of N-nitroso intetermediate produced by nitrosation on the nitrogen atom of C=N. We have found that some α-ketooximes reacted with dinitrogen tetroxide to give cyclic compounds of furoxan derivatives in excellent yields under mild conditions (0~ -40℃) in acetonitrile or tetrahydrofuran. The reaction appears to be initiated via the oxidation of oxime (C=NOH) to the nitrile oxide (CEN→0). Thus, dinitrogen tetroxide is a good reagent for the deoximation and cyclization reaction under mild conditions.