Sosnovskikh, V. Ya.; Esafov, V. I.; Andreev, N. S. Journal of Organic Chemistry USSR (English Translation), 1981 , vol. 17, # 11 p. 2096 - 2100 Zhurnal Organicheskoi Khimii, 1981 , vol. 17, # 11 p. 2346 - 2350