Electrochemically induced Diels–Alder reaction of p-benzoquinone with 1,3-cyclopentadiene

The electrochemical oxidation of 1,4-hydroquinone has been studied in the presence of 1,3-cyclopentadiene as the diene in water/ethanol (40/60) using cyclic voltammetry and controlled-potential coulometry methods. The results revealed that the dienophile derived from oxidation of hydroquinone participates in two successive Diels–Alder reactions with cyclopentadiene and via an pathway converts into the 1,4,4a,5,8,8a,9a,10a-octahydro-(1,4),(5,8)-dimethano-9,10-anthraquinone in a good yield without any toxic reagents at the carbon electrode in a simple cell. Also, we describe the kinetic evaluation of a compound from [4 + 2] cycloaddition reaction of electrochemically generated p-benzoquinone with 1,3-cyclopentadiene.