(3β,20α)-17β-Hydroxy-9-methoxy-16β-methoxycarbonylyohimban 4-oxide

This alkaloid has been obtained from Alstonia venenata and is laevorotatory with [α]²⁵_D - 58.20° (H2O). The ultraviolet spectrum in EtOH has absorption maxima at 224, 268 and 291 mJi. The base forms a hydrochloride, m.p. 26S-6°C (dec.) and an unstable red picrate, m.p. 222-3°C (dec.). Catalytic hydrogenation over PtO2 in MeOH, reduction with Zn in AcOH or with ferrous sulphate yields Venenatine (q.v.), m.p. 130°C (dec.).

Govindachari et al., Tetrahedron Lett., 902 (1964)