Enantioselective synthesis of (−)-phaseic acid

Phaseic acid (PA) has long been considered an inactive oxidation catabolite of the essential plant hormone abscisic acid (ABA). However, a recent study disclosed that PA actually acts as an ABA receptor agonist and is capable of prolonging ABA effects in vivo. Here, we report a simple, enantioselective synthesis of (−)-phaseic acid. Key transformations of our strategy include a facile hydrozirconation reaction and a critical, Mn(III)-catalyzed allylic oxidation.