Highly convergent route to cyclopeptide alkaloids. Total synthesis of ziziphine N

A highly convergent protocol to cyclopeptide alkaloids, as demonstrated by the first total synthesis of antiplasmodial agent ziziphine N, is developed. The key elements include construction of its aryl ether unit via Mitsunobu reaction, installation of its enamide part via CuI/N,N-dimethylglycine-catalyzed coupling reaction, and ring closure with coupling agents such as FDDP and DPPA.