1. S. P. Korshunov, N. A. Kudryavtseva, G. I. Shalyapina, A. V. Zemlyanskaya, and N. V. Korzhova, Zh. Organ. Khim., 8, 1913 (1972).
2. W. Ried and P. Stahlhofen, Ber., 90, 815 (1957).
3. J. B. Ekkley and R. J. Wells, Ber., 38, 2259 (1905).
4. Quan Dang Quoc, R. Caujolle, and Thi Bang Tam Dang, Compt. Rend., C, 272, 1518 (1971).
5. W. Ried and E. König, Ann., 755, 24 (1972).