1. Ya. I. Mel'nik and N. I. Zemlyanskii, Zh. Obshch. Khim.,40, 791, 1015 (1970).
2. N. I. Zemlyanskii, Ya. I. Mel'nik, and V. V. Turkevich, ibid.,42, 1269 (1972).
3. V. V. Turkevich and I. F. Viblyi, Zh. Prikl. Spektr.,6, 77 (1966).
4. A. P. Boisselle and N. A. Meinhardt, J. Org. Chem.,27, 1828 (1962).
5. R. S. Edmundson, Tetrahedron,20, 2781 (1964).