1. Faculty of
Pharmaceutical Sciences, Hiroshima International University, 5-1-1 Hirokoshingai,
Kure, Hiroshima 737-0112, Japan
2. Department of Synthetic Organic
Chemistry, Graduate School of Medical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8553,
Japan