A--The eIectrochemica1 reduction of IHS& in dimethyl formamide (DMF) in the presence. old&rem alkylating agents and supporting electrolytes lead to the formation of products derived from alkylation at oxygen (Eand Z-dialkoxy stilbene), alkylation at carboo (alkylated henzoin derivatives) and from a reaction with the solvent DMF followed bv alkvlation and cvclisation to 2-methoav-45diohenvl-1.3-dioxole. The relative amounts of these productshepe& very much-on the supporting eleckoiyte, ;he aikyl&ing agent and its concentration. LiCl in small concentrations. (C,H &NC1 and a large excess of dimnhyl sulfate favor the formation of the dioxole derivative. LiCl in lark ~o&trations and alkylating agents o&r than dimethyl sulfate favor alkylatioo at oxygen and/or carbon. The results of the preparative electrolysis under various conditions are described. INTRODlJ43lON The electrochemical reduction of benzil has been investigated under various conditions. In protic media cis-and trams-stilbene dial is formed followed by tautomerization to benzoin[i-31. In DMF two separated one-electron reduction steps can he observed which merge into a single two-electron process in the presence of lithium cations[4,5]. Ryan and Evans investigated the reduction of be&l in DMF and acetonitrile ' _ G. T. Moss, G. Crank and F. W. Eastwood, J. cti See.. them. corrvnwr 206 (197OL &know/e&elnent -We gratefully acknowledge the financial support by the Deutsche Forschungsgemeinsshaft.