Acid-Catalyzed Condensation of Citronellal and Electron Rich Phenols: Mechanism and Functionalization of the Adducts

Citronellal was condensed with a number of electron rich phenols, affording either adducts of the benzo(di)furan or benzo(di)oxocane type. Functionalities could be introduced on the benzodifuran at the 8-position by using either 2-substituted resorcinols or by reactions of preformed benzodifuran. The mechanism of the formation of the adducts was investigated.