1: With polystyrene-based selenenyl bromide resin in dichloromethane T=0 - 25°C; 0.333333 h; 2: With dihydrogen peroxide in tetrahydrofuran T=25°C; 0.333333 h; Further stages.;

sodium hydride in tetrahydrofuran T=25°C;

potassium carbonate in acetone 0.333333 h; Heating;