photo-Bergman cyclization

Intramolecular photoinduced cyclization of enediynes leading to aromatic compounds.
Notes:
  1. The solvent plays a key role in the reaction efficiency and product distribution. The reversibility of the initial photoreaction and competing radical vs ionic pathways dictate product distribution, in stark contrast to the thermal process.
  2. This reaction is particularly attractive in molecular biology and molecular medicine. In particular, it permits the expeditious synthesis of core synthones of great diversity.
Source:
PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 384