Synthesis of 5,5′-bis-benzofurans and 5-arylbenzofurans

A facile synthetic route of the tandem Claisen rearrangement/aerobic Wacker-type oxidative cyclization toward 5,5′-bis-benzofurans 2 and 5-arylbenzofurans 3 starting with bis-allyl aryl ethers 4 or allyl aryl ethers 5 with good yields is described. Skeletons 4 or 5 was prepared from 4,4′-biphenol (1) in moderate total yields via the known protocol.