1. J. Alkonyi, Chem. Ber., 96, 1873 (1963).
2. W. F. Erman, J. Org. Chem.,32, 765 (1967).
3. B. A. Arbuzov, Z. G. Isaeva, and V. V. Ratner, Izv. Akad. Nauk SSSR, Ser. Khim., 644 (1962).
4. V. V. Ratner, Z. G. Isaeva, and B. A. Arbuzov, Izv. Akad. Nauk SSSR, Ser. Khim., 2766 (1969).
5. G. H. Whitham, J. Chem. Soc., 2232 (1961).