Formation of 6,6'-(Butane-1,4-diyl)bis(1,2,3,4-tetrahydronaphthalene) in the reaction of tetralin with aluminium chloride

Abstract

It has been shown that the reaction of aluminium chloride with tetralin yields 6,6'-(butane-1,4-diy1)-bis(1,2,3,4-tetrahydronaphthalene) as well as a number of other products. It is suggested that this compound is formed by protonation of tetralin, fragmentation of the alicyclic ring and then electrophilic attack of a further tetralin molecule. The positions of substitution in the product suggests that ion pairs are involved in the reaction. It is clear that intermediates have sufficient lifetime to undergo intermolecular substitution reactions in addition to intramolecular substitution or proton loss.