Preparation and separation of all possible rotamers of a stereochemical analog of meso -tartaric acid: optically inactive and optically active isomers of ( R , S )-2,2′-bis(methoxycarbonyl)-6,6′-dimethyl-9,9′-bitriptycyl
was opticallyinactive Ci conformation. The other opticalactive forms were resolved to give a pair of enantiomers, which were characterized by optical rotation and CD spectra. Thus the opticalinactivity of a compound such as meso-tartaric acid that can take Ci conformation in solution, is now ascribed to that the molecule has an opticallyinactive Ci conformer and equal amounts of optically active