Influence of Z,E-isomerism on the chiral-optical properties of amides

Article abstract of DOI:10.1007/BF01165725

The study of the chiral-optical properties of N-acyl-(-)-1-methyl-1,2,3,4-tetrahydroisoquinolines and their acyclic analogs, the n-acyl-(-)-1-phenylethylamines, with the known ratio of Z- and E-isomers showed that the Z-isomers are characterized by the negative Cotton effect in the region of the absorption band of the amide chromophore. The observed Cotton effects of amides of phenylethy lamine, which are higher by comparison with those of amides of tetrahydroisoquinoline, are explained by the interaction of the amide and aromatic chromophores, which are in proximity in certain conformations, possible for acyclic conformationally free phenylethylamides. 1997 Plenum Publishing Corporation.