Ruthenium-catalyzed alkyne-propargyl alcohol addition.: An asymmetric total synthesis of (+)-α-kainic acid

graphic A novel route to the neuroexcitatory amino acid, kainic acid, is developed. The key concept derives from a ruthenium-catalyzed cycloisomerization of a tethered alkyne-propargyl alcohol to form a cylic 2-vinyl-1-Acyl compound. A single stereocenter introduced by an asymmetric reduction of a ketone sets the stage for all the other stereocenters. A novel 1,6-addition of silyl cuprate serves to install a hydroxyl group at the diene termines.