Yoon, Youn-Jung; Joo, Jae-Eun; Lee, Kee-Young; Kim, Yong-Hyun; Oh, Chang-Young; Ham, Won-Hun Tetrahedron Letters, 2005, vol. 46, # 5 p. 739 - 741 doi: 10.1016/j.tetlet.2004.12.025