title: NMR spectroscopic determination of preferred conformations of quinidine and hydroquinidine.
abstract: NMR spectra of quinidine (I), hydroquinidine (II), and their respective acetyl derivatives (III and IV) were compared. The chemical shifts of some protons in I differed from those of their counterparts in II. These values were concentration dependent in I and II; they were similar in III and IV but not concentration dependent. The implications of these findings and the correlation of the NMR data with the preferred conformations are discussed.
mesh_terms: D000107:Acetylation; D055598:Chemical Phenomena; D002621:Chemistry; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011802:Quinidine / Q000031:analogs & derivatives*
chemical_list: D011802:Quinidine