Reitz,D.B. et al.
Journal of the American Chemical Society, 1978 , vol. 100, p. 5428 - 5436

Klimko, Yu. E.; Isaev, S. D.; Yurchenko, A. G.
Russian Journal of Organic Chemistry, 1995 , vol. 31, # 2 p. 166 - 170
Zhurnal Organicheskoi Khimii, 1995 , vol. 31, # 2 p. 191 - 195

Seyferth, Dietmar; Hui, Richard C.
Tetrahedron Letters, 1984 , vol. 25, # 25 p. 2623 - 2626