1. Laboratory of Organic Chemistry, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
2. R & D Center, Organo Corporation, 4-4-1 Nishionuma, Minami-Ku, Sagamihara, Kanagawa 252-0332, Japan
3. Laboratory of Organic Chemistry, Daiichi University of Pharmacy, 22-1 Tamagawa-machi, Minami-ku, Fukuoka 815-8511, Japan