Gornostaev, L. M.; Es'kin, A. P.; El'tsov, A. V. Journal of Organic Chemistry USSR (English Translation), 1988 , vol. 24, # 12 p. 2352 - 2357 Zhurnal Organicheskoi Khimii, 1988 , vol. 24, # 12 p. 2604 - 2611