Wang, Qian; Fan, Shi Yan; Wong, Henry N. C.; Li, Zhong; Fung, Bing M.; Twieg, Robert J.; Nguyen, Huu Tinh Tetrahedron, 1993, vol. 49, # 3 p. 619 - 638 doi: 10.1016/S0040-4020(01)86265-7