Direct correlation between complex conformation and chiral discrimination upon inclusion of amino acid derivatives by β- and γ-cyclodextrins

GRAPHICS A correlation between the conformation and chiral recognition characteristics of a series of modified amino acid complexes with beta- and gamma-cyclodextrins has been determined, using titration microcalorimetry and H-1 NMR techniques. The enantiomeric discrimination (D or L) is found to be dependent on the adoption of one of two distinct conformations. With the magnitude of the chiral discrimination (K-D/K-L) arising from the guest's depth of penetration into the host's cavity.