Peracid induced ring opening of some isoxazolidines and oxidation of saturated 1,3-oxazines to new heterocyclic nitrones

Article abstract of DOI:10.1016/S0040-4020(98)00789-3

The regiochemistry of peracid-induced ring opening of a number of isoxazolidines is investigated. The mechanism of the ring opening reaction and the effects of substituents on the regiochemical behavior have been discussed. The oxidation process gives an equilibrium mixture of nitrone and its six-membered ring hydroxylamine tautomer; the ratio of which is found to depend on the substituents. The tautomeric cyclic hydroxylamine has been convened to a new class of nitrones by oxidation with mercury (II) oxide or p-benzoquinone. One of the cyclic hydroxylamine lacking hydrogen at the α- carbons has been oxidized to nitroxide spin label.