1. Graduate School of Pharmaceutical SciencesTohoku University 6-3 Aza-aoba, Aramaki Aoba-ku Sendai 980–8578 Japan
2. Synthetic Organic Chemistry LaboratoryRIKEN Cluster for Pioneering Research 2-1 Hirosawa Wako Saitama 351-0198 Japan
3. Institute of Medicinal ChemistryHoshi University 2-4-41 Ebara, Sinagawa-ku Tokyo 142-8501 Japan