Murakami, Nobutoshi; Wang, Weiqi; Aoki, Masashi; Tsutsui, Yasuhiro; Sugimoto, Masanori; Kobayashi, Motomasa Tetrahedron Letters, 1998, vol. 39, # 16 p. 2349 - 2352 doi: 10.1016/S0040-4039(98)00151-8