1. D. L. Pain and R. Slack, J. Chem. Soc., No. 6, 5166 (1965).
2. ?Broad-spectrum agent,? Japanese Patent No. 59-12676; Tokyo Koho, No. 3, 317 (1984); in: Izobret. SSSR Rubezhom, No. 22, 138 (1984).
3. F. Fischer and H. Riese, J. Prakt. Chem., 12, 177 (1961).
4. O. Diels, Berichte, 47, 2186 (1914).
5. Weygand-Hilgetag, Experimental Methods in Organic Chemistry [Russian translation], Khimiya, Moscow (1968), p. 99.