Shchepin, V. V.; Gladkova, G. E.; Russkikh, N. Yu. Journal of Organic Chemistry USSR (English Translation), 1992 , vol. 28, # 6.1 p. 902 - 907 Zhurnal Organicheskoi Khimii, 1992 , vol. 28, # 6 p. 1156 - 1162