1: n-butyllithium; 1-methoxy-allene With copper(l) iodide in diethyl ether; hexane T=-40°C; 0.5 h; 2: allyl bromide in tetrahydrofuran; diethyl ether; hexane T=-30°C; 1 h;

1: 1-methoxy-allene; n-Bu2CuLi in diethyl ether; hexane T=-40°C; 0.5 h; 2: allyl bromide in tetrahydrofuran; diethyl ether; hexane T=-65 - -40°C;