A number of 3-hydroxy substituted indolic nitrones were found to quantitatively photorearrange to (2-benzoylamino)phenyl ketones upon UV-A irradiation. EPR-Spin Trapping experiments suggest that the process, which is believed to proceed via the formation of an oxaziridine, follows a homolytic pathway. Although DFT calculations do not allow to totally exclude alternative routes involving singlet intermediates