1. Laboratoire de Chimie Organique, ESPCI ParisTech, CNRS, 10 rue Vauquelin, 75231 Paris Cedex 05, France, Sanofi, Process Development, 45 chemin de Mételine, BP 15, 04201 Sisteron Cedex, France, Sanofi-Aventis Deutschland GmbH, Chemistry & Biotechnology Development (C&BD) Frankfurt Chemistry Industriepark Hoëchst, Building G 838, 65926 Frankfurt am Main, Germany