Smith III, Amos B.; Zhuang, Linghang; Brook, Christopher S.; Lin, Qiyan; Moser, William H.; Lee Trout, Robert E.; Boldi, Armen M. Tetrahedron Letters, 1997, vol. 38, # 50 p. 8671 - 8674 doi: 10.1016/S0040-4039(97)10500-7