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.