Light-induced and related reactions of quinones. Part VIII. Some (2-hydroxyalkyl)-, phenethyl-, (2-ethoxycarbonylethyl)-, and styryl-1,4-benzoquinones

Abstract

The synthesis of 1,4-benzoquinones carrying, severally, the side-chains [CH₂]₂·OH, CH₂·CH(OH)Me, [CH₂]₂·Ph, CH₂·CHPh₂, [CH₂]₂·CO₂Et, CH₂·CH(CO₂Et)₂, cis- and trans-CHCHPh, CHCPh₂, and CO·CHCHPh is described. When irradiated with visible light the hydroxyalkylquinones yield the corresponding carbonyl compounds. The phenyl-, diphenyl-, and ethoxycarbonyl-ethylquinones and the β-phenylstyrylquinone give 2,3-dihydrobenzofurans. Mechanisms are discussed. Diethyl (1,4-benzoquinonyl)methylmalonate is essentially unchanged. The remaining quinones afford unidentified amorphous products.