1. School of Chemistry; University of Nottingham; University Park Nottingham NG7 2RD UK
2. GlaxoSmithKline Medicines Research Centre; Gunnels Wood Road Stevenage SG1 2NY UK
3. Lilly; UK Erl Wood Manor Windlesham GU20 6PH UK
4. Departamento de Química Orgánica; Universidade de Vigo; 36310 Vigo Spain