Total Syntheses of rac- and (+)-Goniomitine

Concise total syntheses of rac- and (+)-goniomitine were developed. The cyanide-catalyzed imino-Stetter reaction of an aldimine, derived from ethyl 2-aminocinnamate and either rac- or (S)-alpha,beta-unsaturated aldehyde bearing a delta-valerolactam at the beta-position, provided rac- or (S)-indole-3-acetate carrying an alpha-vinyl-delta-valerolactam scaffold at the 2-position, respectively. Subsequent saturation of the vinyl group, followed by treatment with DIBAL-H, afforded N-benzyl protected goniomitine. Final debenzylation provided the desired natural product after only three column separations.