Synthesis 2001(8): 1114-1116
DOI: 10.1055/s-2001-15074
SHORTPAPER
© Georg Thieme Verlag Stuttgart · New York

Investigations of Cascade Cyclizations of Terpenoid Polyalkenes via Radical Cations. A Biomimetic-type Synthesis of (±)-3-Hydroxy-spongian-16-one

Frank Goeller, Christoph Heinemann, Martin Demuth*
Max-Planck-Institut für Strahlenchemie, P.O. Box 101365, 45413 Mülheim an der Ruhr, Germany
Fax: +49(208)3063951; e-Mail: demuthm@mpi-muelheim.mpg.de;
Further Information

Publication History

Received 21 March 2001
Publication Date:
24 September 2004 (online)

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.

8

Xing, X.; Demuth, M. J. Am. Chem. Soc., accepted.

15

Goeller, F. Ph. D. Thesis; Max-Planck-Institut für Strahlenchemie/University of Essen: Germany, in progress.