The Effect of a Hydroxy Protecting Group on the PtCl2-Catalyzed Cyclization of Dienynes—A Novel, Efficient, and Selective Synthesis of Carbocycles Acknowledgement is made to the EU for the COST D12 Action “Cascade Free Radical Reactions” and for a short-term scientific mission to Madrid (EM). We thank Nieves Arroyo (CSIC) for preliminary experiments, Dr. J. Vaissermann (UPMC) for the X-ray analysis of 3 e, Dr. M. L. Jimeno (CNQO) for NMR studies on 3 a, Dr. M.-N. Rager (ENSCP) for NMR studies on 3 h, 6, and 11, and Matthieu Bernard (UPMC) for performing some of the experiments. We also thank Dr. Emmanuel Lacôte and Dr. Henri Rudler (UPMC) for helpful discussions.

The versatile ketone C can be obtained by hydrolyzing cyclooctene B, which is formed in a PtCl2-catalyzed cycloisomerization reaction from the enyne precursor A. A carbene platinum complex is invoked in the process, which also represents one of the few efficient syntheses of functionalized cyclooctanes from acyclic precursors. Supporting information for this article is available on the WWW under http: //www. wiley-vch. de/contents/jc₂002/2002/z18566ₛ. pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.