1: isopropenyl bromide With tert.-butyl lithium in diethyl ether; pentane T=-78°C; 0.416667 h; Inert atmosphere; 2: 3-ethoxy-2-cyclohexen-1-one in diethyl ether; pentane T=-78 - 20°C; Inert atmosphere;

in tetrahydrofuran; diethyl ether T=-78°C; 0.166667 h;

in tetrahydrofuran; diethyl ether 4 h; Ambient temperature;

in tetrahydrofuran; dimethyl sulfoxide Ambient temperature;