Total Syntheses of (+)‐Villocarine A, (−)‐Apogeissoschizine, and (+)‐Geissoschizine

Abstract

AbstractTotal syntheses of geissoschizine‐type monoterpenoid indole alkaloids (MTIAs) are reported. An intramolecular Pictet‐Spengler cyclization was developed for the selective construction of the 3R stereocenter. The first total synthesis of (+)‐villocarine A was then achieved. Furthermore, the first total synthesis of the highly strained (−)‐apogeissoschizine was also accomplished in an aza‐Michael cyclization/E1cB elimination/stereoselective olefin isomerization sequence. Finally, (+)‐geissoschizine, a common biosynthetic intermediate of MTIAs, was obtained from apogeissoschizine through ring‐opening along with a release of ring strain.