Abstract: Upon direct photolysis esters 1-6 undergo the following reactions: fragmentation to carbenes (followed by their collapse to allenes, furans and cyclopropenes), rearrangement to cyclopentenes and ring expansion to bicyclo [2.1. O] pentanes. Ring opening to dienic esters and deconjugation, a reaction characteristic of simple cu,@-unsaturated esters, are not important general pathways. In methanol-0-d double bond migration in 2 to give ethyl ...
