Abstract
The results of acid catalyzed epimerization of (-)-2'-benzoylemetine, which possesses the same configuration as the original alkaloid, and of reduction of 2'-benzoyl-5, 11b-dehydroemetinium salt, and the presence of trans-quinolizidine bands in infrared spectra of (-)-2'-acylemetines suggested that (-)-emetine should be represented by (Ia) or (IV), alternatively. The large negative contribution of C-11b hydrogen of (-)-2'-acylemetine to the [M]D value gave evidence for (Ia) as the absolute configuration of (-)-emetine.
