Regioselective propargylation of aldehydes and ketones by electrochemical reaction using zinc and aluminum anodes

Electrochemical propargylation of aldehydes and ketones with unsubstituted or cc-substituted propargylic bromides using platinum cathode and zinc anod e proceeded efficiently under mild conditions to give the corresponding hom opropargyl alcohols exclusively in high yields. Similar electrochemical pro pargylation with gamma-substituted propargyl bromides gave the correspondin g homoallenyl alcohols as major products. Regioselectivity in the introduct ion of a propargyl or an allenyl group was controlled simply by a change of the anode material, zinc or aluminum. (C) 2000 Elsevier Science Ltd. All r ights reserved.