1: With hydrogenchloride; trifluoroacetic acid; sodium nitrite in water T=0 - 4°C; 1 h; 2: With sulfur dioxide; copper(l) chloride; copper dichloride in acetic acid T=-15 - 0°C; 15 h;

1: With n-butyllithium; Di-n-butylmagnesium in tetrahydrofuran T=-10°C; Inert atmosphere; 2: With sulfuryl dichloride in tetrahydrofuran; toluene T=-10 - 10°C;