Back, Thomas G.; Baron, Denise L.; Luo, Weide; Nakajima, Suanne K.
Journal of Organic Chemistry, 1997 , vol. 62, # 4 p. 1179 - 1182

Krief, A.; Dumont, W.; Clarembeau, M.; Bernard, G.; Badaoui, E.
Tetrahedron, 1989 , vol. 45, # 7 p. 2005 - 2022