chromium(VI) oxide; Montmorillonite K 10 in dichloromethane T=-15°C; 3.5 h;

1: Ph3P / propan-2-ol / 24 h / Ambient temperature 2: pyridine 3: 75 percent / Bu3SnH, AIBN / benzene / 2 h / 80 °C 4: 82 percent / 1,8-diazabicyclo-<5.4.0>undec-7-ene (DBU) / benzene / 3 h / Ambient temperature View Scheme

triphenylphosphine in isopropyl alcohol 24 h; Ambient temperature;

1: Ph3P / propan-2-ol / 24 h / Ambient temperature 2: pyridine View Scheme

1: Ph3P / propan-2-ol / 24 h / Ambient temperature 2: pyridine 3: 75 percent / Bu3SnH, AIBN / benzene / 2 h / 80 °C View Scheme