Akhmatdinov, R. T.; Kantor, E. A.; Imashev, U. B.; Yasman, Ya. B.; Rakhmankulov, D. L. Journal of Organic Chemistry USSR (English Translation), 1981 , vol. 17, # 4 p. 626 - 630 Zhurnal Organicheskoi Khimii, 1981 , vol. 17, # 4 p. 718 - 723