Enyne [4 + 4] photocycloaddition with polycyclic aromatics

Abstract

Polycyclic aromatics undergo [4 + 4] photocycloaddition to give substituted cyclooctadiene products. We have examined the [4 + 4] photoreactivity of these aromatics with enynes using a recently developed substitution pattern that undergoes a 1,3-hydrogen migration, forming a single cycloadduct. Several substrates yield stable, isomerized [4 + 4] adducts.