Formal Synthesis of Corynanthe Indole Alkaloid (±)‐Mitralactonine: Construction of α‐Hydroxy‐Keto Functionalized Tetracyclic Skeleton

ABSTRACT An efficient synthesis of a tetracyclic skeleton common to many corynanthe alkaloids was accomplished in 10 linear steps starting from a known tetrahydro β‐carboline intermediate. The tetracyclic α‐hydroxy keto functionalized advanced precursor of (±)‐mitralactonine was realized using Wittig olefination, ketohydroxylation of a trisubstituted alkene, and a tandem amine unmasking‐intramolecular nucleophilic displacement reaction for C–N bond formation of C/D‐rings.