Intramolecular photochemical reactions

Photochemical reactions of pyridazines, phthalazines and cinnolines were extensively reviewed in CHEC-I 84CHEC-l(3B)l , with many reactions proceeding via ring contraction. Since 1985, the photolysis of 4-azidopyridazines to give significant yields of ring expansion products, unsaturated 

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Intramolecular photochemical reactions need the presence of light sensitive groups such as carbonyls to induce transformations by oc-cleavage (Norrish I reaction) or by y-H-abstraction (Norrish II reaction). 

Hoffmann, N. and Pete, J.-P. (1995) Intramolecular photochemical reactions of 3-Alkenyloxyphenols. Tetrahedron Letters, 36, 2623-2626. 

Shinto, T., Tajima, f., Suishu, T., and Somekawa, K. (1991) Intramolecular photochemical reactions of 4-(alkoxycarbonyl group at the olefinic carbon chain. Journal of Organic Chemistry, 56, 7150-7154. 

Griesbeck, A. G. The link between stereoselectivity and spin selectivity in intermolecular and intramolecular photochemical reactions. J. Photosci. 2003,10, 49-60. 

Intramolecular photochemical reactions involving oxirane C-C bonds are also known, the yields are somewhat lower than in comparable carbocyclic systems. 

Gan, H., Kellet, M.A., Leon, J.W., Kloeppner, L.R., Leinhos, U., Gould, I.R., Farid, S., and Whitten, D.G., Novel intermolecular and intramolecular photochemical reactions initiated by excited state single electron transfer processes, /. Photochem. Photobiol. A Chem., 82, 211, 1994. 

Matlin, A.R., George, C.F., Wolff, S., and Agosta, W.C., Regiochemical control in intramolecular photochemical reactions of 1,6-heptadienones carbonyl-substituted l-(4-alkenyl)-l-cyclo-pentenes, /. Am. Chem. Soc., 108, 3385-3394,1986. 

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