A Divergent Polyene Cyclization for the Total Synthesis of Greenwayodendrines,Greenwaylactams, Polysin and Polyveoline |
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Authors: | Immanuel Plangger Dr. Tobias Pinkert Dr. Klaus Wurst Prof. Dr. Thomas Magauer |
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Affiliation: | 1. Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria;2. Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria These authors contributed equally to this work.;3. Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria |
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Abstract: | We present a concise asymmetric total synthesis (5–8 steps) of nine sesquiterpenoid alkaloids featuring four different tetra-/pentacyclic scaffolds. To this end, a novel, bioinspired indole N-terminated cationic tricyclization has been developed, enabling the divergent synthesis of greenwayodendrines and polysin. Subtle variation of the C2-substituted indole cyclization precursor allowed switching between indole N- and C-termination. For the latter, a subsequent Witkop oxidation enabled conversion of the cyclopentene-fused indole into the eight-membered benzolactam to directly furnish the family of greenwaylactams. In addition, a diastereomeric C-termination product has been elaborated to provide access to polyveoline. |
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Keywords: | Alkaloids N-Termination Natural Products Polyene Cyclization Total Synthesis |
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