PREPARATION AND THERMAL-DECOMPOSITION OF N,N'-DIACYL-N,N'-DIALKOXYHYDRAZINES - SYNTHETIC APPLICATIONS AND MECHANISTIC INSIGHTS

Oxidation of various O-alkyl hydroxamates 1 where R(1) was a keto-meth oxime, benzoyl, aryl, or alkyl group with eerie ammonium nitrate (CAN) or nickel peroxide (NiO2 . H2O) leads to the corresponding esters in high yield. This augurs well for the facile synthesis of highly hinder ed esters. Dimers of type 2 were identified as intermediates in these oxidations, and a combination of experimental and theoretical results suggest that these dimers decompose in a stepwise 1,1-elimination mann er via intermediate nitrenes to furnish the esters and not via a stepw ise 1,2-elimination sequence as previously thought.