Takizawa, Toshiya; Watanabe, Kazuhiro; Narita, Koichi; Kudo, Kyosuke; Oguchi, Takamasa; Abe, Hideki; Katoh, Tadashi Heterocycles, 2008, vol. 76, # 1 p. 275 - 290 doi: 10.3987/COM-07-S(N)5