Novel synthesis of oxadiazinone and oxadiazepinone derivatives by ring expansion of diaziridinone

Treatment of N,N'-di-tert-butyldiaziridinone with alpha-hydroxy ketones in the presence of a catalytic amount of BF3. OEt2 gave carbazate derivatives in excellent yields. Acid-catalyzed recyclization of these compounds easily proceeded to give oxadiazinone derivatives. The reaction was applicable to the synthesis of oxadiazepinone derivatives and also to one-pot process.