Stereocontrolled intramolecular iron-mediated tandem [6+2]-ene-type diene/dienol ether double cyclization reactions

A stereocontrolled intramolecular iron-mediated diene/diene tandem double cyclocoupling reaction has been explored using vinyl ethers as the olefin partners. Diastereomerically pure spirotricyclic products with functionalized (alkoxymethyl) side chains can be formed efficiently under photothermal conditions. With a methoxy substituent on the iron-complexed cyclohexadiene core, demetallation and acidic hydrolysis of the cyclocoupling product afforded a cyclohexenone ring.