Petrov, K. A.; Rudnev, G. V.; Sorokin, V. D. Journal of Organic Chemistry USSR (English Translation), 1990 , vol. 26, # 10 p. 1791 - 1794 Zhurnal Organicheskoi Khimii, 1990 , vol. 26, # 10 p. 2074 - 2078