Promotion of selectivity through organised media:Fries rearrangement of calix (n) arene esters(n=4,6,8)

摘要

Fries migration of various calix(n)arene esters (n=4,6,8) under the influence of different solvents (benzene, nitrobenzene, chlorobenzene, carbon disulphide, toluene, xylene, mesitylene) and Lewis acid catalysts (aluminium chloride, ferric chloride and boron trifluoride etherate) has been examined. It appears that the best conditions for ht econversion of calix(n)arene esters to p-acyl calix(n)arenes involve the use of aluminium chloride as the Lewis acid and carbon disulphide or benzene as solvent. The use of toluene or mesitylene as a solvent leads to regioselective formation of their acyl derivatives probably through the intermediacy of a host guest complex of the solvent with calix(n)arenes.