Collect. Czech. Chem. Commun. 1986, 51, 1731-1742

(-)-Strempeliopine, stereoselective total synthesis and the determination of absolute configuration

Josef Hájíček and Jan Trojánek

Research Institute for Pharmacy and Biochemistry, 194 04 Prague 9


A synthesis of (±)-strempeliopine (II) is described, the key step of which is the stereoselective reductive rearrangement of 18-methylene-1,2-dehydroaspidospermidine (XI). The absolute configuration of the natural (-)-base II was determined as (2S, 7R, 20R, 21R) on the basis of its synthesis from (+)-18-methylenevincadifformine (XVII) the configuration of which was derived from a comparison of circular dichroism properties of bases with a β-anilinoacrylate chromophore. The biogenesis of the alkaloids of the schizozygane type is discussed.