References and Notes.

1 (a) Cimino, G.; Puliti, R.; Scognamiglio, G.; Spinella, A.; Trivellone, E. Pure & Appl. Chem. 1989, 61, 535. (b) Cimino, G.; Mattia, C. A.; Mazzarella, L.; Puliti, R.; Scognamiglio, G.; Spinella, A.; Trivellone, E. Tetrahedron 1989, 45, 3863.

2 For reviews of the 1,3-dipolar cycloadditions of azomethine ylides, see: (a) Lown, J. W. In 1,3-Dipolar Cycloaddition Chemistry; Padwa, A., Ed.; Wiley: New York, 1984, Vol. 1, Chapter 6. (b) Tsuge, O.; Kanemasa, S. In Advances in Heterocyclic Chemistry; Katritzky, A. R., Ed.; Academic: San Diego, 1989, Vol. 45, p. 231. (c) Huisgen, R. Angew. Chem. 1980, 92, 979. (d) Huisgen, R. Angew. Chem., Int. Ed. Engl. 1963, 2, 565. (e) Padwa, A. In Comprehensive Organic Synthesis, Semmelhack, M. F.; Ed.; Pergamon Press: Oxford, 1991, Vol. 4, p. 1069. (f) Wade, P. A. In Comprehensive Organic Synthesis, Semmelhack, M. F.; Ed.; Pergamon Press: Oxford, 1991, Vol. 4, p. 1111.

3 (a) Elks, J.; Elloitt, D. F.; Hems, B. A. J. Chem. Soc. 1944, 626. (b) Kostyanovskii, R. G.; Rudchenko, V. F.; Prosyanik, A. V. Izv. Akad. Nauk. SSSR, Ser. Khim. 1977, 565.

4 (a) Rooney, C. S.; Rokach, J.; Atkinson, J. G. U. S. Patent 4 112 112, 1978. (b) Maryanoff, B. E.; Reitz, A. B.; Duhl-Emsweiler, B. A. J. Am. Chem. Soc. 1985, 107, 217.

5 Henke, B. R.; Kouklis, A. J.; Heathcock, C. H. J. Org. Chem. 1992, 57, 7056.

6 Sisko, J.; Weinreb, S. M. J. Org. Chem. 1991, 56, 3210.

7 Wilson, S. R.; Sawicki, R. A. J. Org. Chem. 1979, 44, 287.

8 Griffith, D. A.; Heathcock, C. H. Tetrahedron Lett. 1995, 36, 2831.

9 Nakagawa, M.; Tonozuka, M.; Obi, M.; Kiuchi, M.; Hino, Y. Synthesis 1974, 510.

10 Meyers, A. I.; Himmelsbach, R. J.; Reuman, M. J. J. Org. Chem. 1983, 48, 4053.

11 McMurry, J.E.; Rico, J.G.; Shih, Y-n. Tetrahedron Lett. 1989, 30, 1173.

12 Kato, N.; Nakanishi, K.; Takeshita, H. Bull. Chem. Soc. Jpn. 1986, 59, 1109.

13 Freudenberger, J.H.; Konradi, A.W.; Pedersen, S.F. J. Am. Chem. Soc. 1989, 111, 8014.

14 (a) Jin, H.; Uenishi, J-i.; Christ, W.J.; Kishi, Y. J. Am. Chem. Soc. 1986, 108, 5644. (b) Kishi, Y. Pure Appl. Chem. 1992, 64, 343.

15 Takai, K.; Kimura, K.; Kuroda, T.; Hiyama, T.; Nozaki, H. Tetrahedron Lett. 1983, 24, 5281.

16 Schreiber, S. L.; Meyers, H. V. J. Am. Chem. Soc. 1988, 110, 5198.

17 Nicolaou, K. C.; Ramphal, J. Y.; Palazon, J. M.; Spanevello, R. Angew. Chem., Int. Edn. Engl. 1989, 28, 587.

18 Schwartz, J.; Labinger, J. A. Angew. Chem. Int. Ed. Engl. 1976, 6, 333.

19 Cassar, L. J. Organomet. Chem. 1975, 93, 253.

20 Seyferth, D.; Marmor, R. S.; Hilbert, P. J. Org. Chem. 1971, 36, 1379.

21 Takai, K.; Nitta, K.; Utimoto, K. J. Am. Chem. Soc. 1986, 108, 7408.

22 Verkruijsse, H. D.; Hasselaar, M. Synthesis 1979, 292.

23 Corey, E. J.; Kang, J.; Laguzza, B. C. Tetrahedron Lett. 1983, 24, 4913.

24 Alani, M.; Ferri, F.; Linstrumelle, G. Tetrahedron Lett. 1993, 34, 6403.