Methyl 2-methoxycarbonyl-4-isopropyl-3-pyrrolepropionate (II) was derived to its potassium salt, reacted with ethyl chloroformate to form methyl 1-ethoxycarbonyl-2-methoxy carbonyl-4-isopropyl-3-pyrrolepropionate (III), which was reduced with platinum oxide catalyst to effect reduction to the pyre olidine ring, and finally hydrolyzed to obtain 2-carboxy-4-isopropyl-3-pyrrolidinepropionic acid (V), corresponding to homodihydrokainic acid.
