Kigoshi, Hideo; Ojika, Makoto; Suenaga, Kiyotake; Mutou, Tsuyoshi; Hirano, Junko; Sakakura, Akira; Ogawa, Takeshi; Nisiwaki, Masanori; Yamada, Kiyoyuki Tetrahedron Letters, 1994, vol. 35, # 8 p. 1247 - 1250 doi: 10.1016/0040-4039(94)88035-2