Sakai, Yasuhiro; Oikawa, Masato; Yoshizaki, Hiroaki; Ogawa, Tomohiko; Suda, Yasuo; Fukase, Koichi; Kusumoto, Shoichi Tetrahedron Letters, 2000, vol. 41, # 35 p. 6843 - 6847 doi: 10.1016/S0040-4039(00)01158-8