Wu, Bin; Hua, Zihao; Warren, J. David; Ranganathan, Krishnakumar; Wan, Qian; Chen, Gong; Tan, Zhongping; Chen, Jiehao; Endo, Atsushi; Danishefsky, Samuel J. Tetrahedron Letters, 2006, vol. 47, # 31 p. 5577 - 5579 doi: 10.1016/j.tetlet.2006.05.086