Improved Synthesis of Larger Resorcinarenes

The synthesis of the larger resorcin[5 and 6]arene macrocycles [5]OMe and [6]OMe has been realized by a Lewis acid-catalyzed condensation of 1,3-dimethoxy-2-methylbenzene with paraformaldehyde in o-dichlorobenzene as the solvent. The methoxy-resorcin[5 and 6]arenes were quantitatively demethylated by treatment with BBr3 to obtain the corresponding macrocycles with free OH groups. X-ray studies showed that in the solid state both the conformation and the packing of [6]OMe and [5]OMe are driven by C–H···O, C–H···π, and π···π interactions.