Institution: | 1. Organic Synthesis, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium), Fax: (+32)?3265‐3233;2. Ecole Normale Supérieure, Département de Chimie, UMR CNRS‐ENS‐UPMC 8640, 24 Rue Lhomond, 75231 Paris Cedex 5 (France), Fax: (+33)?1‐44‐3224‐02 |