Regioselective electroreduction of the aromatics, including methoxybenzenes, by using LiClO4 as a supporting electrolyte in an aprotic solvent (THF) containing alcoholic proton donors such as t-BuOH was successfully achieved to afford the corresponding 1,4-cyclohexadienes regioselectively in high yield. The electrolysis can, be performed under constant current conditions at ambient temperature. The effect of electrode materials was remarkable, that is, the use of Mg electrodes gave the best result. Moreover in the presence of t-BuOD instead of t-BuOH, the deutrated 1,4-cyclohexadienes were obtained in high deuterium incorporation at 1- and 4-positions. A direct electron transfer to the aromatics is unlikely, and it is reasonable that the solvated Li(0), which is generated by the cathodic reduction of LiClO4, is intermediately involved in the electron transfer with being assisted by the anodically generated Mg2+ as an electron transfer catalyst. (C) 2003 Elsevier Science Ltd. All rights reserved.