Regularities of Oxidation Reactions of Sulfolanopyrazolidines and Sulfolanoisoxazolidines with Bromine

It has been established that the bromine action on bicyclic derivatives of nitrosulfolane with pyrazolidine and isoxazolidine rings under mild conditions leads to the oxidation of the nitrogen-containing heterocycle with the formation of isomeric sulfolanopyrazolines and sulfolanoisoxazolines. The structure of the obtained compounds was established by IR, 1H NMR, 13C{1H}, 1H–13C HMQC, 1H–13C HMBC, 1H–1H NOESY spectroscopy.