1. C. R. Smith, J. Amer. Chem. Soc.,50, 1936 (1928).
2. A. P. Orechoff and D. Brodsky, Ber.,66, 466 (1933).
3. A. S. Sadykov, M. Karimov, and Kh. A. Aslanov, Zh. Obshch. Khim.,33, 3414, 3417 (1963).
4. M. A. Rubtsov, L. N. Yakhontov, and E. E. Mikhlina, Zh. Obshch. Khim.,35, 621 (1965).
5. F. Haglid, Acta Chem. Scand.,21, 579 (1967).