1. Sykes, P.J., Rutherford, F.G., Laing, S.B., Phillips, J.H., and Turnbull, J.P., Tetrahedron Lett., 1971, p. 3393.
2. Pestovskii, S.N., Ananchenko, S.N., and Rzheznikov, V.M., Izv. Ross. Akad. Nauk, Ser. Khim., 1987, p. 1197.
3. Rzheznikov, V.M., Ivanenko, T.I., Fedotov, V.P., Pestovskii, S.N., and Ananchenko, S.N., Khim.-Farm. Zh., 1988, no. 12, p. 1462.
4. Kirk, D.N. and Slade, C.J., J. Chem. Soc., Perkin Trans. 1, 1984, p. 2595.
5. Elyakov, G.B., Stonik, V.A., Kuznetsova, T.A., and Mikhailov, V.V., Bioorg. Khim., 1992, vol. 18, p. 1424.