1. Graduate School of Pharmaceutical Sciences, Osaka University, 1-6, Yamada-oka, Suita, Osaka 565-0871, Japan
2. A Laboratory of Organic Chemistry, Gifu Pharmaceutical University, 1-25-4-Daigaku-nishi, Gifu 501-1196, Japan
3. Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan