1: 75 percent / DBU / 1,2-dichloro-ethane / Ambient temperature 2: trimethylsilyl trifluoromethanesulfonate / 1,2-dichloro-ethane / 0.08 h / Ambient temperature 3: 95 percent / Bu4NF / tetrahydrofuran / Ambient temperature View Scheme

1: 75 percent / DBU / 1,2-dichloro-ethane / Ambient temperature 2: trimethylsilyl trifluoromethanesulfonate / 1,2-dichloro-ethane / 0.08 h / Ambient temperature 3: 95 percent / Bu4NF / tetrahydrofuran / Ambient temperature 4: 88 percent / pyridine / Ambient temperature View Scheme