Smirnova, O. B.; Cherkaev, G. V.; Shekhtman, N. M. Journal of Organic Chemistry USSR (English Translation), 1991 , vol. 27, # 11.2 p. 2123 - 2127 Zhurnal Organicheskoi Khimii, 1991 , vol. 27, # 11 p. 2391 - 2395