Dialkylcuprates react with propargyl chlorides to form allenes in generally excellent yield. The mixed n-butylmethyl-and tert-butylmethylcuprates react to preferentially transfer the n- butyl (67: 29) and tert-butyl (97: 3) groups, the latter providing an excellent means for the synthesis of tert-butylallenes. Small amounts of coupled product derived froni the dialkylcuprates are formed, along with allene formally derived by net reduction of the ...
