1.1: sulfuryl dichloride / dichloromethane / 2 h / 25 °C 2.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / dichloromethane / 0.17 h 2.2: 24 h / 25 °C 3.1: ammonium fluoride / methanol / 16 h / 25 °C 4.1: ammonia; water / 1 h / 55 °C 5.1: methanol / 1 h / 55 °C 6.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 55 °C View Scheme