AbstractHerein, we describe the first total synthesis of (+)‐cornexistin as well as its 8‐epi‐isomer starting from malic acid. The robust and scalable route features a Nozaki–Hiyama–Kishi reaction, an auxiliary‐controlled syn‐Evans‐aldol reaction, and a highly efficient intramolecular alkylation to form the nine‐membered carbocycle. The delicate maleic anhydride moiety of the nonadride skeleton was constructed from a β‐keto nitrile. The developed route enabled the synthesis of 165 mg (+)‐cornexistin.