T=-78°C;

1: With zinc(II) chloride in tetrahydrofuran T=-3°C; 0.0833333 h; 2: With N,N'-dimethyl-N,N'-propyleneurea in tetrahydrofuran T=20°C; 3 h; 3: With hydrogenchloride in tetrahydrofuran T=20°C; 4 h;

ethylene dibromide in tetrahydrofuran T=20°C; 1 h;

in diethyl ether refluxing for 2 h;;