1. Terashima, M., Ishi, M., and Kanaoka, Y., Synthesis, 1982, p. 484
2. Tauer, E. and Grellmann, K.H., J. Org. Chem., 1981, vol. 46, p. 4252
3. Achkasova, A.A. and El’chaninov, M.M., Khim. Geterotsikl. Soedin., 2006, p. 191.
4. Mel’nikova, E.B., El’chaninov, M.M., Milov, A.A., and Luk’yanov, B.S., Khim. Geterotsikl. Soedin., 2008, p. 1331.
5. Kornilov, M.Yu., Ruban, E.M., Fedchuk, V.N., Starinskaya, E.V., and Buznik, M.V., Zh. Org. Khim., 1973, vol. 9, p. 2577