NMR Spectroscopic Determination of Preferred Conformations of Quinidine and Hydroquinidine

Synthesis of 10, 11-Dihydroxydihydroquinidine N-oxide, a New Metabolite of Quinidine. Preparation and 1H-nmr Spectroscopy of the Metabolites of Quinine and Quinidine and Conformational Analysis via 2D COSY NMR Spectroscopy

“…Although extensive nmr studies have been reported in the literature with regard to the structures of quinine [la] and quinidine [lb] (9)(10)(11), only rarely has this involved their metabolites (12). This is especially relevant with respect to the assignment of the *H-nmr spectrum of the quinuclidine ring, which exhibits a large degree of signal overlap and complex coupling patterns.…”

Impact of Stable Conformation of Cinchona Alkaloids on Protonation Site

“…Purification of Commercial I and V-Purification was carried out according to a procedure described previously (4). Table I lists the NMR data.…”