Cyclopropanation of Benzene Rings by Oxidatively Generated α‐Oxo Gold Carbene: One‐Pot Access to Tetrahydropyranone‐Fused Cycloheptatrienes from Propargyl Benzyl Ethers

Cyclopropanations of benzene rings by oxidatively generated α-oxo gold carbenes are for the first time demonstrated in a Buchner reaction, in which readily available propargyl benzyl ethers are converted in one-pot to tetrahydropyranone-fused cycloheptatrienes via sequential oxidative gold catalysis and base-promoted isomerization. Additional examples of arene cyclopropanations without fragmentation of the cyclopropane ring are also realized