Chemistry of the chippiine/dippinine/tronocarpine class of indole alkaloids.

The chippiines/dippinines/tronocarpine are a family of biologically and structurally interesting polycyclic tryptamine-derived indole alkaloids isolated from the leaf and bark extracts of plants belonging to the Tabernaemontana genus. To date, 14 members of this family have been isolated and characterized. This review discusses the isolation, structure determination, biological activity, and proposed biosynthesis of these metabolites. In addition, synthetic studies on the alkaloids are described including approaches to tronocarpine and dippinine B core intermediates and total syntheses of (+)-dippinine B and (+)-tronocarpine.