4- Cyano-l-methoxynaphthalene

Al-Jalal reported that the photocycloaddition of l-cyano-4-methoxynaph-thalene with alkenes commonly occurs at the 1,2 bonds of the naphthalene ring [126,131], However, when 2-cyano-6-methoxynaphthalene (52) was treated with 2-chloroacrylonitrile, ( )-ethoxyacrylonitrile, or ( )-cinnamonitrile, the (2 + 2) cycloadducts showed a different regiochemistry [132,133] (Scheme 21). Irradiation of 52 in the presence of ethyl vinyl ether or ( )-dichloroethene did not give a cross-adduct, but gave a photodimer of 52. 

Illumination of 1-methoxynaphthalene in media containing cyanide ion gives a good yield of l-cyano-4-methoxynaphthalene (and very little 1-cyanonaphthalene) whereas photocyanation of naphthalene itself proceeds with only small yields (Lok and Havinga, 1974). 

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