Synthesis of Furan and Benzene Fused 2-Tetralones via Photo-Induced Rearrangement of 2′-(Furan-2-yl)-[1,1′-Biphenyl]-4-ols

A concise method for the synthesis furan and benzene fused 2-tetralones via photo-induced rearrangement of 2 '-(furan-2-yl)-[1,1 '-biphenyl]-4-ols was developed. Under argon atmosphere and room temperature, 6,7-dihydrophenanthro[9,10-b]furan-5(4H)-ones were obtained by irradiating 2 ' -(furan-2-yl)-[1,1 '-biphenyl]-4-ols with a 254 nm UV lamp (64 W) in dichloromethane (DCM) for 1 hour. The reaction mechanism includes 6 pi-electrocyclization, thermal suprafacial [1,5]-H shift, double thermal suprafacial [1,3]-H shift and keto-enol isomerization.

Automated summary

A concise method for the synthesis of furan and benzene fused 2-tetralones via photo-induced rearrangement has been developed. The reaction mechanism involves several key steps including electrocyclization, [1,5]-H shift, [1,3]-H shift and keto-enol isomerization.