Ruppert,I. Tetrahedron Letters, 1977 , p. 1987 - 1990 Full Text View citing articles Show Details Gorbatenko,V.I. et al. Journal of Organic Chemistry USSR (English Translation), 1976 , vol. 12, # 10 p. 2047 - 2051 Zhurnal Organicheskoi Khimii, 1976 , vol. 12, # 10 p. 2103 - 2107