Effect of Strain on Singlet Oxygen (¹O₂) Reactions. 2. Photooxidation of Methylenecyclopropanes

In contradistinction to methylenecyclopropanes 2-4 which are inert to ¹O₂, 2, 2-diphenylmethylenecyclopropane (1) reacts sluggishly, producing benzophenone as the only isolable product. On the other hand 1, 1-dimethyl- and 1, 1-dicyclopropylmethylenecyclopropanes 5 and 6 yield a variety of products (depending on the reaction conditions) whose formation is explicable in terms of secondary rearrangements of an initially formed allylic hydroperoxide.