The chemistry of ortho-benzoquinones. Part III. Reactions with furans and an isobenzofuran

Abstract

The reactions of tetrachloro-1,2-benzoquinone and 1,2-benzoquinone with furan, 2-methylfuran, and 2,5-diphenylfuran are reported. Dihydrofurobenzodioxin adducts are isolated in most cases. The reaction of 1,2-benzoquinone with 2-methylfuran is shown to be solvent dependent; in the presence of a trace of ethanol, addition of ethanol to the dihydrofurobenzodioxin takes place. A two-step mechanism is proposed and exemplified by the observed ring-opening reaction of the quinones with an isobenzofuran.