... 1660 M.-1. Ramirez, D. Garey, and MR Peña, Vol. 32 G. Hunsmann, and G. Holfe, LiebigsAnn. ... [3] TD Cyr and GA Poulton, Can. J. Chenu, 56, 1796 (1978). [4] JD Hepworth, Vol 3, in Comprehensive Heterocyclic Chemistry, Vol 3, AR Katritzky and С W. Rees, eds, 1984, p 789. ...