Complex formation of fenchone with α-cyclodextrin: NMR titrations

(13)C NMR titration studies of inclusion complexes of bicyclic terpenoid, fenchone enantiomers with α-cyclodextrin revealed their 1:2 guest–host stoichiometry. Sequential binding constants were determined indicating a strong binding cooperativity of two α-cyclodextrin to fenchone. The overall association constants were used to calculate the Gibbs free energies of diastereomeric complex formation, which might be used as a measure of chiral recognition of fenchone by α-cyclodextrin. These results were compared with corresponding data derived for camphor, which is an isomeric bicyclic terpenoid. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10847-013-0356-4) contains supplementary material, which is available to authorized users.