Synthesis of (-)-Kainic Acid

Significance

(-)-Kainic acid, isolated from the Japanese marine alga Digena simplex, has been used for stimulation of nerve cells and imitation of some neurological disease states. Key points of the synthesis are: (1) ring-closing metathesis of D and (2) formation of the pyrrolidine ring via highly diastereoselective intramolecular Michael addition (F → G).