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

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