The enantioselective synthesis of maoecrystal V, a cytotoxic polycyclic diterpene, is described. Key reactions in the synthesis include an intramolecular Heck reaction, an oxidative cycloetherification, and an intermolecular Diels–Alder reaction to forge the carbocyclic core in a concise and stereoselective manner. Late-stage amine and C–H oxidation is used to install the final functional groups required to complete the synthesis.