Nagao, Yoshimitsu; Sano, Shigeki; Morimoto, Kenji; Kakegawa, Hisao; Takatani, Tadanobu; Shiro, Motoo; Katunuma, Nobuhiko Tetrahedron Letters, 2000, vol. 41, # 14 p. 2419 - 2424 doi: 10.1016/S0040-4039(00)00177-5