sulfur T=190°C;

1: 78 percent / LiAlH4 / diethyl ether / 2 h / Ambient temperature 2: 0.25 h / Ambient temperature 3: LiBr, hexamethylphosphoric triamide (HMPA) / tetrahydrofuran / 6 h / Heating View Scheme

lithium aluminium tetrahydride in diethyl ether 2 h; Ambient temperature;

1: 78 percent / LiAlH4 / diethyl ether / 2 h / Ambient temperature 2: 0.25 h / Ambient temperature 3: LiBr, hexamethylphosphoric triamide (HMPA) / tetrahydrofuran / 6 h / Heating 4: 57 percent / tributylstannane, azobisisobutyronitrile / benzene / 16 h / Heating View Scheme