Cyclic gamma-iminolactones can be identified among the more abundant products of the fast photolysis of 2,4,5,6-tetrachloro-1,3-dicyanobenzene (1) in absolute ethanol with an unfiltered UV high pressure lamp. A number of other photolytes accounted for the material balance of the experiment. The preliminary identification of the products was secured by mass spectrometry after separation by capillary gaschromatography and also on a comparative basis with the mass spectra of their oxo-analogs. A rationale is offered for some discrepances of comparison of individual photolites and in some departures from a close correlation with end products of previous findings from the present experiments.
