Divergent Total Syntheses of Lycorine Alkaloids via a Sequential C-H Functionalization Strategy.

A Pd-catalyzed one-pot sequential C-H functionalization strategy was utilized to prepare four lycorine alkaloids and one -lycorine alkaloid from the common intermediate . By switching the followed oxidative conditions of air, DMSO/HO/I, and DMSO/O, based on the Pd(PPh)/KCO/toluene catalytic system, three key intermediates , , and with different substitution patterns could be obtained in a well-controlled manner. As a result, four natural products γ-lycorane, hippadine, anhydrolycorinone, and anhydrolycorine as well as a -lycorine alkaloid Δ-6-oxodihydrolycorine were successfully synthesized within 10 steps through this divergent route.