Synthesis of substituted phenols by using the ring-closing metathesis/isoaromatization approach

Ring-closing olefin metathesis (RCM) of 4-methylene-1,7-octadien-3-ones 2, followed by isomerization of the carbon--carbon double bond of 6-methylene-2-cyclohexenones 3 from exo to endo, produced various phenols 4. As an application of the method, the RCM/Mizoroki-Heck reaction of 2 was proven to be also effective for the synthesis of phenols having an additional substituent at ortho-benzylic position.