Reactivity of N-phenacyloxycarbamates and related systems in the presence of bases: study of a new [1,2] anionic rearrangement

N-Phenacyloxycarbamates and other systems containing a CH2–O–N framework, in the presence of bases, undergo a CH2–O–N→ CH(OH)–N rearrangement. The mechanism of this reaction has been studied kinetically and through crossover and capture experiments. The bulk of the data favours an intermolecular ionic mechanism which occurs by removal of a proton from the methylene group in the rate-determining step, followed by interaction between a glyoxal molecule and a carbamate anion in the fast step of the reaction.