RESUMO
(±)-Aspidospermidine (1) has been synthesized from the commercially available 2,3-dihydro-1H-carbazol-4(9H)-one 6 in 10 steps with 20% overall yield. The key step of the strategy is a one-pot carbonyl reduction/iminium formation/intramolecular conjugate addition reaction that may be applied for the synthesis of other Aspidosperma alkaloids.
Assuntos
Alcaloides Indólicos/síntese química , Quinolinas/síntese química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Alcaloides Indólicos/química , Espectroscopia de Prótons por Ressonância Magnética , Quinolinas/química , Espectrometria de Massas por Ionização por Electrospray , EstereoisomerismoRESUMO
Bioinspired total synthesis of gymnothelignan N was accomplished in 13 steps and 6.7% overall yield. The synthesis features a syn Evans aldol reaction, an intramolecular hydrogenative dehydration reaction, and a phenol oxidative dearomatization/Friedel-Crafts reaction, which provides a new plausible biosynthetic pathway for the gymnothelignans and other symbiotic members. Meanwhile, another tetrahydrofuran-type lignan beilschmin A was also synthesized.
