1. For summaries, discussions, and additional references with respect to such preparative methodologies, see: (a) Avendano, C.; Menendez, J. C. Kirk-Othmer 'Encyclopedia of Chemical Technology'; Wiley-Interscience: New York, 1995; Vol. 13, p. 512;
2. Trigo, G. G. Adv. Heterocyclic Chem. 1985, 38, 177
3. (e) Ware, E. Chem. Rev. 1950, 46, 403.
4. (a) Avendano, C.; Menendez, J. C. Kirk-Othmer 'Encyclopedia of Chemical Technology'; Wiley-Interscience: New York, 1995; Vol. 13, p. 512;
5. (b) Guella, G.; Mancini, I.; Zibrowius, H.; Pietra, F. Helv. Chim. Acta 1988, 71, 773;