potassium hydroxide in ethanol T=50°C; 2 h;

1: 1.) magnesium turnings, iodine, 2.) tellurium shot / 1.) THF, reflux, 0.5 h, 2.) reflux, 3 h 2: 1.) sodium borohydride / 1.) THF, ethanol, 2.) room temperature, 0.5 h 3: 96 percent / aq. potassium hydroxide / ethanol / 2 h / 50 °C View Scheme

1: 1.) sodium borohydride / 1.) THF, ethanol, 2.) room temperature, 0.5 h 2: 96 percent / aq. potassium hydroxide / ethanol / 2 h / 50 °C View Scheme

1: 1.) sodium nitrite, hydrobromic acid, 2.) cuprous bromide / 1.) 5 min, 2.) reflux 2: 1.) magnesium turnings, iodine, 2.) tellurium shot / 1.) THF, reflux, 0.5 h, 2.) reflux, 3 h 3: 1.) sodium borohydride / 1.) THF, ethanol, 2.) room temperature, 0.5 h 4: 96 percent / aq. potassium hydroxide / ethanol / 2 h / 50 °C View Scheme