1: formamide With diphosphorus pentasulfide in ethylene glycol dimethyl ether T=65°C; 0.166667 h; 2: 1-bromohex-5-en-2-one in ethylene glycol dimethyl ether T=65 - 110°C; 1.66667 h; 3: With hydrogenchloride; dihydrogen peroxide more than 3 stages;