Meketa, Matthew L.; Mahajan, Yogesh R.; Weinreb, Steven M.
Tetrahedron Letters, 2005 , vol. 46, # 28 p. 4749 - 4751

Levchenko,N.K. et al.
Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1973 , vol. 22, p. 1042 - 1046
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1973 , vol. 22, # 5 p. 1086 - 1090

Karrenbrock,F.; Schaefer,H.J.
Tetrahedron Letters, 1978 , p. 1521 - 1522