Synthesis and Characterization of Atropdiastereomeric Macrocyclic Metacyclophanes

We report the design, synthesis, and characterization of achiral macrocyclic metacyclophanes exhibiting atropdiasteromerism. These macrocycles contain a 1,2,6-trisubstituted benzene in which the 1 position bears an amide group and the 2 and 6 positions are connected by a bridging chain. Because of the hindered rotation about the C(aryl)–C(acyl) bond and C(sp2)–C(sp3) bonds, the CO bond of the amide group may be oriented toward or away from the interior of the macrocycle, resulting in observable and separable stereoisomers.