270. | Nazarov Cyclization Reaction I. N. Nazarov et al., Izv. Akad. Nauk S.S.S.R., Otd. Khim. Nauk 1942, 200. Protic or Lewis acid-catalyzed electrocyclic ring closure of divinyl ketones, or their equivalents, to yield 2-cyclopentenones: Silicon-directed cyclizations to α-methylenecyclopentanones: H. T. Kang et al., Tetrahedron Letters 33, 3495 (1992). Diastereoselectivity of interrupted reaction: J. A. Bender et al., J. Org. Chem. 63, 2430 (1998); idem et al., J. Am. Chem. Soc. 121, 7443 (1999); H. Hu et al., ibid. 121, 9895 (1999). Lewis acid catalyzed reactions: C. Kuroda et al., Chem. Commun. 1997, 1177; H. A. Buchholz, A. de Meijere, Eur. J. Org. Chem. 1998, 2301. Reviews: S. E. Denmark, Comp. Org. Syn. 5, 751-784 (1991); K. L. Habermas et al., Org. React. 45, 1-158 (1994); S. Giese, F. G. West, Tetrahedron Letters 39, 8393 (1998); of interrupted reaction: D. Zuev, L. A. Paquette, Chemtracts 12, 1019-1025 (1999). |