1. PPSM, ENS Cachan, CNRS UMR8531,
61 av President Wilson, F-94230 Cachan, France
2. A. E. Favorsky Irkutsk Institute
of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky Str., Irkutsk 664033, Russian
Federation
3. Centre de Recherches
de Gif sur
Yvette, Institut de Chimie des Substances Naturelles, UPR2301-CNRS,
1 avenue de la Terrasse, 91198 Gif sur Yvette cedex France