Reactions of cyclohexadienes. Part XIII. Catalytic conversion of 1-methoxycyclohexa-1,4-dienes into 1-methoxycyclohexa-1,3-dienes

Abstract

Dichloromaleic anhydride, aluminium chloride, and toluene-p-sulphonic acid, are active catalysts in promoting conjugation of 1-methoxycyclohexa-1,4-dienes to the 1,3-isomers. Experimental procedures involved are simple, and since the 1,4-dienes are conjugated in situ they are directly capable of Diels–Alder reactions with suitable dienophiles under mild conditions. Examples are given.