1: 3,3-dimethyl-butan-2-one With potassium hydride in tetrahydrofuran Metallation; 0.25 h; 2: carbon disulfide With bis(trimethylsilyl)-sulfide in tetrahydrofuran Substitution; 0.333333 h; 3: With 1,2,2-trichloro-1,1,2-trichloro-ethane in tetrahydrofuran T=0°C; Oxidation; 0.5 h;

tetraphosphorus decasulfide; bis-trimethylsilyl ether; sulfur in xylene 8 h; Heating;

sulfur in benzene T=155 - 160°C; 3 h;

1: 1.05 M potassium tert-butoxide / dimethylformamide; benzene / 1 h / Ambient temperature 2: 1.) N-chlorosuccinimide; 2.) (Me3Si)2S, imidazole / 1.) CH2Cl2, 0 deg C, 20 min; 2.) CH2Cl2, RT, 18 h View Scheme

sulfur Heating;