Photooxygenation of 2-methoxy-3-methyl-2-cyclopenten-l-one (1) gives both ene and dioxetane products. The product distribution depends on temperature and solvent. In CD30D, the photooxygenation of 1 gives solvent adducts as initial products, and the ratio of stereoisomers is very sensitive to the amount of CD, OD in the reaction mixture. The results are discussed in terms of possible intermediates for the ene and dioxetane products, ...
