Lolya, D. O.; Gailite, V. A.; Freimanis, Ya. F.; Liepinya, A. Ya.; Turnovskii, I. V.; et al. Journal of Organic Chemistry USSR (English Translation), 1985 , vol. 21, p. 1914 - 1923Zhurnal Organicheskoi Khimii, 1985 , vol. 21, # 10 p. 2091 - 2101