Affiliation: | 1. Institut für Organische Chemie, Fakult?t für Chemie und Mineralogie, Universit?t Leipzig, Johannisallee 29, 04103 Leipzig (Germany), Fax: (+49)?341‐973‐6599;2. Laboratory of Organic Chemistry, Department of Chemistry, University of Thessaloniki, 54124 Thessaloniki (Greece) |