[1] GSK, Via Fiorentina 1, I-53100 Siena, Italy
[2] CIC BioGUNE, Bizkaia Technol Pk, Bldg 800, Derio 48160, Spain
[3] Leiden Univ, Dept Bioorgan Synth, NL-2333 Leiden, Netherlands
[4] Basque Fdn Sci IKERBASQUE, Bilbao 8009, Spain
[5] Univ Basque Country, Fac Sci & Technol, Dept Organ Chem 2, Leioa 48940, Spain