(untitled) - Aoyagi, Y; Inoue, A; Koizumi, I; Hashimoto, R; Tokunaga, K; Gohma, K; Komatsu, J; Sekine, K; Miyafuji, A; Kunoh, J; Honma, R; Akita, Y; Ohta, A (Heterocycles, 1992)