1. A. N. Kost, G. A. Golubeva, and R. G. Stepanov, Zh. Obshch. Khim., 32, 2240 (1962).
2. E. A. Yatsynich, D. V. Petrov, V. A. Dokichev, and Yu. V. Tomilov, Zh. Org. Khim., 41, 1187 (2005).
3. А. Otto, B. Ziemer, and Y. Liebscher, Synthesis, 965 (1999).
4. H. Sasaki and E. M. Carreira, Synthesis, 135 (2000).
5. I. V. Kostyuchenko, E. V. Shulishov, V. A. Korolev, and V. A. Dokichev, Izv. Akad. Nauk, Ser. Khim., 2482 (2005).