1. Present Address: Department of Chemistry, Illinois State University, Normal, IL 61790-4160.
2. Telephone: (716) 645-6800, ext. 2194. Fax: (716) 645-6963. E-mail: jrichard@chem.buffalo.edu.
3. Keeffe, J. R.; Kresge, A. J. InThe Chemistry of Enols; Rappoport, Z., Ed.; John Wiley and Sons: Chichester, 1990; pp 399−480.