Li, Xiao-Qiang; Jia, Mu-Xin; Wang, Xiao-Zhong; Jiang, Xi-Kui; Li, Zhan-Ting; Chen, Guang-Ju; Yu, Yi-Hua Tetrahedron, 2005, vol. 61, # 40 p. 9600 - 9610 doi: 10.1016/j.tet.2005.07.075