Stereocontrolled total synthesis of (-)-kainic acid.

[reaction: see text] A stereocontrolled total synthesis of (-)-kainic acid is described. A fully functionalized trisubstituted pyrrolidine ring was constructed by ring-closing metathesis of an acrylate derivative followed by an intramolecular Michael addition of the resultant alpha,beta-unsaturated lactone with high diastereoselectivity. Two alternative protocols for the construction of the alpha,beta-unsaturated lactone were also developed.