Topology of the photochemical ‘bicycle’ reaction. Mechanistic and exploratory organic photochemistry

Abstract

We report some new examples of the ‘bicycle’ reaction, the corresponding quantum yields and exceptionally rapid S1 reaction rates, evidence for lack of clockwise bicycling but in favour of an overshoot plus backup mechanism to account for loss of stereochemistry, a test excluding an even number of pivot steps as alternative to bicycling, and the effect of interposition of an aromatic unit along the track.