Conformational Behavior of Cinchonidine in Different Solvents: A Combined NMR and ab Initio Investigation

摘要: The conformation of cinchonidine in solution has been investigated by NMR techniques as well theoretically. Three conformers are shown to be substantially populated at room temperature, Closed(1), Closed(2), and Open(3), with the latter being most stable apolar solvents. stability closed relative that however, increases solvent polarity. In polar solvents three have similar energy. relationship between energies dielectric constant is not linear but resembles form an Onsager function. Ab initio density functional reaction field calculations using cavity shapes determined isodensity surface good agreement experiment for which do show strong specific interaction cinchonidine. role conformational behavior illustrated example platinum-catalyzed enantioselective hydrogenation ketopantolactone dif...