1: 1,4-Dihydroxy-2-butyne With potassium hydroxide in water; dimethyl sulfoxide T=20°C; Inert atmosphere; 2: propargyl bromide in water; dimethyl sulfoxide; toluene T=0 - 70°C;

1: 1,4-Dihydroxy-2-butyne With hexacarbonyldicobalt in dichloromethane T=20°C; Nicholas reaction; 1 h; 2: propargyl alcohol With boron trifluoride diethyl etherate in dichloromethane T=20°C; Nicholas reaction; 3: With ammonium cerium(IV) nitrate in acetone T=0°C; Nicholas reaction; 0.166667 h; Further stages.;

potassium hydroxide in dimethyl sulfoxide T=25 - 35°C;

potassium hydroxide in water T=20°C; 4 h;