Biomimetic Total Syntheses of (−)‐Leucoridines A and C through the Dimerization of (−)‐Dihydrovalparicine

Abstract Concise biomimetic syntheses of the Strychnos‐Strychnos‐type bis‐indole alkaloids (−)‐leucoridine A ( 1 ) and C ( 2 ) were accomplished through the biomimetic dimerization of (−)‐dihydrovalparicine ( 3 ). En route to 3 , the known alkaloids (+)‐geissoschizoline ( 8 ) and (−)‐dehydrogeissoschizoline ( 10 ) were also prepared. DFT calculations were employed to elucidate the mechanism, which favors a stepwise aza‐Michael/spirocyclization sequence over the alternate hetero‐Diels–Alder cycloaddition reaction.