Crystalline Structure of N-(S)-2-Heptyl (1R,2R)-2-(2,3-Anthracenedicarboximido)cyclohexanecarboxamide That Differs from Its Preferred Conformation in the Solvent Used for Crystallization

Abstract

The crystalline structure of N-(S)-2-heptyl (1R,2R)-2-(2,3-anthracenedicarboximido)cyclohexamide (1), which was crystallized from methanol, was determined by an X-ray analysis and had a different conformation from its preferred one in CD₃OD by a ¹H-NMR analysis. Inter- and intra-molecular CH-π interaction in a crystal plays a very important role in crystal packing. The preferred conformation of the amide derivative in a solution allows us to exploit (1R,2R)-2-(2,3-anthracenedicarboximido)cyclohexanecarbonyl chloride as a conversion reagent to determine the absolute configuration of chiral amines by ¹H-NMR.