Synthesis of Oxatricyclooctanes via Photoinduced Intramolecular Oxa-[4+2] Cycloaddition of Substituted <i>o</i>‑Divinylbenzenes

The photolysis of substituted <i>o</i>-divinylbenzenes promotes a one-step and metal-free conversion to oxatricycles at room temperature. Irradiation <i>o</i>-divinylbenzenes results in an pericyclic reaction to form cyclic <i>o</i>-quinodiemthane intermediates, which subsequently undergo intramolecular oxa-[4+2] cycloaddition to form oxacyclic derivatives