Photocycloaddition of ethenes to cyanoanisoles
1988; Elsevier BV; Volume: 44; Issue: 5 Linguagem: Inglês
10.1016/s0040-4020(01)85924-x
ISSN1464-5416
AutoresNader A. Al-Jalal, Andrew Gilbert, Peter Heath,
Tópico(s)Photochromic and Fluorescence Chemistry
ResumoAbstract The photoreactions of 2-,3-, and 4-cyanoanisole with cis cyclo-octene, ethyl vinyl ether and acrylonitrile have been investigated. Additions of the cyclo-alkene reflect control of the reaction by the methoxy group to give predominantly meta cycloadducts by 2,6-attack. In contrast these arenes and ethyl vinyl ether undergo ortho cycloaddition which in the case of the product from the 2-arene isomer, leads to a convenient high yield synthesis of the bicyclo[4.2.0]octa-2,7-diene (23). The reactions of acrylonitrile with 2- and 3-cyanoanisoles are slow and non-selective but ortho cycloadducts are formed from the 4-isomer which also undergoes novel photoaddition with the cyano group of both acrylonitrile and benzonitrile to give azacyclo-octatetraenes.
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