Key points are not available for this paper at this time.
In contrast to the general photochemical unreactivity of the 6-aza-analogues of uracils and thymines, 2,4-dimethyl-1,2,4-triazine-3,5(2H)-dione undergoes acetone-sensitized regioselective cycloaddition to ethyl vinyl ether yielding labile azetidine cycloadducts.
Hyatt et al. (1972) studied this question.