Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco, San Sebastián, Spain, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom, and Research Chemistry, Syngenta, Jealott’s Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom, and Syngenta Crop Protection AG, Schaffhauserstrasse, 4332 Stein, Switzerland (At 2009-05-18)