1. Department of Chemistry, Imperial College London, Exhibition Road, South Kensington,
London SW7 2AZ, U.K.
2. Department
of Chemistry, University of Bath, Claverton
Down, Bath BA2 7AY, U.K.
3. GlaxoSmithKline Medicines Research Center, Gunnels Wood Road, Stevenage, Hertfordshire
SG1 2NY, U.K.