Light-induced and related reactions of quinones. Part IV. Reactions of some p-quinones with aliphatic and aromatic aldehydes

Abstract

The mono-, di-, and tri-methyl homologues of 1,4-benzoquinone, and acetyl- and 2,3-dichloro-1,4-benzoquinone all yield acetylquinols when irradiated with visible light in acetaldehyde. 1,4-Benzoquinone yields pivaloylquinol when irradiated in trimethylacetaldehyde. Diacylquinols are additional products in some cases. 1,4-Benzoquinone gives the corresponding aroylquinols with p-t-butyl-, p-methyl-, and p-methoxy-benzaldehyde, but yields a mixture of benzoylquinol and quinol monobenzoate with benzaldehyde; only the corresponding quinol monoesters are formed with p-nitrobenzaldehyde and cinnamaldehyde. Quinizarinquinone yields quinizarin monoesters exclusively. The significance of these results is discussed.