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DOI: 10.1055/s-2001-15074
Investigations of Cascade Cyclizations of Terpenoid Polyalkenes via Radical Cations. A Biomimetic-type Synthesis of (±)-3-Hydroxy-spongian-16-one
Publikationsverlauf
Publikationsdatum:
24. September 2004 (online)
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Abstract
A short and efficient synthesis of the tetracyclic oxygenated diterpene analog of 8, i. e., of 3-hydroxy-spongian-16-one (7), has been achieved in only five steps via a cascade cyclization of the functionalized terpenoid polyalkene 4. Photoinduced electron transfer serves as the pivotal step for selectively creating a radical cation intermediate. Such polycyclizations are radical-driven upon regio- and stereoselective trapping of the radical cation by a nucleophile, such as water in the present case. The overall reaction sequence mimics the non-oxidative biosynthesis of terpenes.
Key words
photoinduced electron transfer - radical cation - biomimetic synthesis - photochemistry - 3-hydroxy-spongian-16-one - radical cyclization - natural products
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References
Xing, X.; Demuth, M. J. Am. Chem. Soc., accepted.
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