(4E,4aS)-4-Ethylidene-4,4a,5,6-tetrahydro-1α-hydroxy-7,16-dimethyl-1H,3H,7H-6β,11cβ-(epoxymethano)-6aα,11bα-(iminoethano)pyrano[4,3-c]carbazol-12-one

Description

The alkaloidal extract of Hunteria urnbellata (K Schum) Stapf. may be treated chromatographically to yield this minor constituent which forms colourless crystals when purified from propanol. It is strongly laevorotatory with [α]_D - 243°. Two methylimino groups, a hydroxyl and a lactone ring are present. The base gives a crystalline O-acetate, m.p. 160°C. The original structure has been revised to that given above on the basis of NMR and mass spectra.

References

Bevan et al., Chern. Ind., 603 (1965) Revised structure: Bevan et al., Tetrahedron, 23,3809 (1967)