1. (a) Black, D. S. C.; Crozier, R. F.; Davis, V. C. Synthesis 1975, 205.
2. (b) Tuffariello, J. J. In Nitrones in 1,3-Dipolar Cycloaddition Chemistry; Padwa, A., Ed.; Wiley Interscience: New York, 1984; Vol. 2, p 1.
3. (c) Carruthers, W. R. Cycloadditions in Organic Synthesis; Pergamon Press: London, 1990; Chapter 6, p 269.
4. (a) Ku, D. H.; Mapanga, F. M.; Khalil, A. M.; Oriaku, T. E.; You, Z.; Lee, H. J.; Huang, K. S.-L. J. Med. Chem. 1997, 37, 313.
5. (b) Huang, K. S.-L.; Lee, E. H.; Olmstead, M. M.; Kurth, M. J. J. Med. Chem. 2000, 65, 499 and references cited therein.