Ring-Construction/Stereoselective Functionalization Cascade: Total Synthesis of Pachastrissamine (Jaspine B) through Palladium-Catalyzed Bis-cyclization of Bromoallenes

Palladium(O)-catalyzed cyclization of bromoallenes bearing hydroxyl and benzamide groups as internal nucleophiles stereoselectively provides functionalized tetrahydrofuran. With this bis-cyclization as the key step, a short total synthesis of pachastrissamine, a biologically active marine natural product, was achieved.