1. Institut Pasteur Université de Paris Cité CNRS UMR3523 Department of Structural Biology and Chemistry Laboratory for Bioorganic Chemistry of Nucleic Acids 28, rue du Docteur Roux 75724 Paris Cedex 15 France
2. Latvian Institute of Organic Synthesis Aizkraukles 21 Riga LV-1006 Latvia
3. Pharmaceutical Division Process Chemistry & Catalysis, Synthetic Molecules Technical Development F. Hoffmann-La Roche Ltd 4070 Basel Switzerland
4. Pharma Research and Early Development Roche Innovation Center Basel F. Hoffmann-La Roche Ltd Grenzacherstrasse 124 4070 Basel Switzerland