Facile synthesis of (+)-α-allokainic acid via Pd-catalyzed hydrogenolysis of allyl acetate derived from trans-4-hydroxy-l-proline

Pd(PPh3)4/PPh3-catalyzed hydrogenolysis of 3a derived from trans-4-hydroxy-l-proline using ammonium formate as a hydride reagent, provides olefin 4 as a major product, which is hydrolyzed to give (+)-α-allokainic acid.