1. I. P. Sheremet and N. F. Komissarenko, Khim. Prirodn. Soedin.,7, 373 (1971).
2. G. Bargellini, Gazz. Chim. Ital.,49, 47 (1919).
3. I. P. Kovalev and V. I. Litvinenko, Khim. Prirodn. Soedin.,2, 233 (1966).
4. B. V. Chandler and K. A. Harper, Austral. J. Chem.,14, 568 (1961).
5. D. W. Fox, W. L. Savage, and S. H. Wender, J. Amer. Chem. Soc.,75, 2504 (1953).