K. Honda, A. Yabe, Hideaki Tanaka
Jul 1, 1975
Citations
0
Influential Citations
4
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The photochemical reactions of dimethyl 1,8-naphthalene diacrylate (I) in solution are found to be cis,trans isomerization and concomitant intramolecular cycloaddition through a triplet state (ET is ca. 40 kcal/mol). Cyclization reaction gives naphtho[1′,8′]bicyclo[3.1.1]hept-2-ene-6-exo,7-endo-dimethyl dicarboxylate (VI), its 6-endo, 7-endo substituted isomer (VII) and cis-anti-naphtho[1′,8′]bicyclo[3.2.0]hept-2-ene-6,7-dimethyl carboxylate (II) in a ratio of ca. 85: 10: 5. Predominant formation of crossed adducts is discussed, taking into consideration the ground-state conformations of (I). Biradical mechanism is proposed for the cyclization to explain the stereochemistry of the crossed products.