THE EFFECT OF THE NATURE OF THE SUBSTITUENT AT THE NITROGEN ATOM ON TRANSFORMATIONS OF 3-BROMO-2,2,6,6-TETRAMETHYL-4-PIPERIDINONE AND ITS 1-HYDROXY AND 1-OXYL DERIVATIVES UNDER CONDITIONS OF THE FAVORSKY REARRANGEMENT

3-Bromo-2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl reacts with NH4OH t o give 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl, a product of the Favorsky rearrangement. 3-Bromo-2,2,6,6-tetramethyl-4-piperidinon e is transformed under these conditions into a bicyclic amino ketone, while its 1-hydroxy derivative affords acyclic nitrosoenone.