Quinolizidines. XXIV. : Syntheses of Ankorine Congeners in Different Oxidation States

8-Hydroxyprotoemetine [(-)-2f], an aldehyde of biogenetic interest, has been synthesized for the first time from the tricyclic ester (-)-5 through the intermediate (-)-6. Wolff-Kishner reduction of (-)-2f produced the 2-ethyl congener (-)-2g. As a result of these syntheses, the circular dichroism (CD) spectra of (-)-2f・HClO_4 and (-)-2g in 0.1 N aqueous HCl and in EtOH, together with those of the Alangium alkaloids ankorine (2d) and alancine (2e), are now availale