Abstract 4, 12-and 4, 14-Dibromo-[2.2] metacyclophane (1 and 2) were prepared by coupling of 1-bromo-2, 4-bis (bromomethyl)-benzene with phenyllithium (isomeric ratio 1∶ 1). Lithiation of the bromides and subsequent carboxylation afforded the isomeric carboxylic acids 3 and 4. 4, 12-Dimethyl-[2.2] metacyclophane (13) is also accessible with 90% stereoisomeric purity by reaction of 2, 4-bis-(chloromethyl) toluene (20) with the Li-salt of 4 ...
