The Photochemical Reaction of 1,2-Naphthoquinones with Aldehydes. III. The Reactions with Aromatic Aldehydes and α, β-Unsaturated Aliphatic Aldehydes

Abstract

Abstract Photochemical reactions of 1,2-naphthoquinone and the substituted derivatives with a variety of aldehydes in the liquid phase have been investigated. The reaction with saturated aliphatic aldehydes gives a mixture of 3-acyl-1,2-naphthalenediol and 1,2-naphthalenediol monoacyl esters. On the other hand, the irradiation of the benzene solution of a 1,2-naphthoquinone derivative and an aromatic aldehyde gives, in general, 1,2-naphthalenediol monoaroyl esters, together with small amounts of other products. Unlike saturated aliphatic aldehydes, α, β-unsaturated aldehydes; i.e., propenal, 2-butenal, trans-2-hexenal, 1-cyclopentenecarbaldehyde, and 1-cyclo-hexenecarbaldehyde, behave similary to the aromatic aldehydes in the photochemical reaction, giving only 1,2-naphthalenediol monoesters. However, 10-undecenal, 3-phenylpropanal, cyclopentanecarbaldehyde, cyclohexanecarbaldehyde, and 3-cyclohexenecarbaldehyde give mixtures of 3-acyl-1,2-naphthalenediols and 1,2-naphthalenediol monoacyl esters similar to those from saturated aliphatic aldehydes. The origin of these significant differences is discussed.