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.