Fujiwara, Kenshu; Goto, Akiyoshi; Sato, Daisuke; Ohtaniuchi, Yuko; Tanaka, Hideki; Murai, Akio; Kawai, Hidetoshi; Suzuki, Takanori Tetrahedron Letters, 2004, vol. 45, # 38 p. 7011 - 7014 doi: 10.1016/j.tetlet.2004.07.145