Catalytic Asymmetric Total Synthesis of (−)‐Galanthamine and (−)‐Lycoramine |
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| Authors: | Lei Li Qiao Yang Dr Yuan Wang Prof Yanxing Jia |
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| Affiliation: | State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Rd. 38, Beijing 100191 (China) |
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| Abstract: | The catalytic asymmetric total syntheses of (?)‐galanthamine ( 1 ) and (?)‐lycoramine ( 2 ) have been achieved by using a conceptually new strategy featuring two metal‐catalyzed reactions as the key steps. A new method for the construction of 3,4‐fused benzofurans has been developed through a palladium‐catalyzed intramolecular Larock annulation reaction, which was successfully applied to the construction of the ABD tricyclic skeleton of 1 and 2 . To achieve the asymmetric synthesis of 1 and 2 , a ScIII/N,N′‐dioxide complex was used to catalyze the enantioselective conjugate addition of 3‐alkyl‐substituted benzofuranone to methyl vinyl ketone for the construction of a chiral quaternary carbon center. |
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| Keywords: | alkaloids asymmetric catalysis natural products palladium total synthesis |
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