1. V. Grenville, D. K. Patel, V. Petrowet al., J. Chem. Soc., 4105 (1957).
2. M. Akhtar and D. H. R. Barton, J. Amer. Chem. Soc.,86, 1528 (1964).
3. V. I. Maksimov and N. M. Goncharova, USSR Author's Certificate No. 232250. Izobreteniya, No. 1, 25 (1969).
4. V. I. Maksimov and N. M. Goncharova, USSR Author's Certificate No. 230812. Izobreteniya, No. 35, 18 (1968).
5. H. Cords, J. Amer Chem. Soc.,75, 5416 (1953).