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Calyciphylline B-Type Alkaloids: Total Syntheses of (-)-Daphlongamine H and (-)-Isodaphlongamine H.

ABSTRACT: The first total synthesis of the complex hexacylic Daphniphyllum alkaloid (-)-daphlongamine H has been accomplished. Key to the success of the strategy are a complexity-building Mannich reaction, efficient cyclizations, and a highly diastereoselective hydrogenation to assemble multigram quantities of the tricyclic core bearing four contiguous stereocenters. Following construction of the hydro-indene substructure by means of a Pauson-Khand reaction, endgame redox manipulations delivered the natural product. Importantly, the synthetic studies have also given access to (-)-isodaphlongamine H and led to a revision of the reported structure of deoxyisocalyciphylline B.

SUBMITTER: Hugelshofer CL

PROVIDER: S-EPMC6750003 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

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Calyciphylline B-Type Alkaloids: Total Syntheses of (-)-Daphlongamine H and (-)-Isodaphlongamine H.

Hugelshofer Cedric L CL Palani Vignesh V Sarpong Richmond R

Journal of the American Chemical Society 20190516 21

The first total synthesis of the complex hexacylic Daphniphyllum alkaloid (-)-daphlongamine H has been accomplished. Key to the success of the strategy are a complexity-building Mannich reaction, efficient cyclizations, and a highly diastereoselective hydrogenation to assemble multigram quantities of the tricyclic core bearing four contiguous stereocenters. Following construction of the hydro-indene substructure by means of a Pauson-Khand reaction, endgame redox manipulations delivered the natur ...[more]

PMID: 31074980

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