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DOI: 10.1055/s-0036-1588560
Efforts Toward a Synthesis of Crotogoudin and Crotobarin
We thank the UC Cancer Research Coordinating Committee for funding initial phases of this research with grant CRC-15-380750 and the NSF for continued funding (CHE-1564340)Publikationsverlauf
Received: 11. Juli 2017
Accepted after revision: 07. August 2017
Publikationsdatum:
16. August 2017 (online)


◊ These authors contributed equally
Published as part of the ISHC Conference Special Section
Abstract
Two synthesis designs for the diterpenoid crotogoudin are discussed, and efforts to achieve each are described. First, a Cope rearrangement/intramolecular Diels–Alder cascade reaction was investigated. Second, a bioinspired sequence of cationic bicyclization and A-ring oxidative fragmentation set-up for a lactonization induced by a phenolic oxidation, ultimately providing a tricyclic intermediate that required only installation of the bridging ring of the salient bicyclo[2.2.2]octane system. This last endeavor was fraught with difficulty, but did lead to the development of conditions for cyclization of related keto-alkenes via manganese(III)-based radical chemistry.
Key words
diterpenoid - cascade - cationic cyclization - phenolic oxidation - dearomatization - Birch reduction - Diels–Alder cycloaddition - radical cyclizationSupporting Information
- Supporting information for this article (Experimental procedures for the synthesis of new compounds from Schemes 2, 3, and 4, and from Equation 1, and their characterization data, are provided) is available online at https://doi.org/10.1055/s-0036-1588560.
- Supporting Information