The synthesis of (-)-isodomoic acid C

The neuroactive algal metabolite (-)-isodomoic acid C, a kainoid amino acid, has been synthesized for the first time. Asymmetric dearomatizing cyclization of an aromatic amide using a chiral lithium amide base generates a bicyclic enone containing a pyrrolidinone ring with the relative and absolute stereochemistry of the target. A further 15 synthetic steps, including conjugate cuprate addition to the enone of a side chain precursor, a Ru-promoted oxidation of the phenyl ring to the C2-carboxylic acid substituent, a regioselective Baeyer-Villiger reaction, and an E-selective Horner-Wadsworth-Emmons reaction, elaborate the cyclization product into the target molecule. Copyright © 2005 American Chemical Society.