1. Department of Chemistry; University of Sheffield; Sheffield S3 7HF U.K.
2. Departamento de Química Organica I; Universidad del País Vasco; San Sebastian 20018 Spain
3. Integrated Drug discovery, R&D; Sanofi Aventis (Deutschland) GmbH; Industriepark Höchst 65926 Frankfurt Am Main Germany
4. Present address: Respiratory, Inflammation, Autoimmunity IMED Biotech Unit; AstraZeneca; Gothenburg Sweden