1: KOH / dimethylsulfoxide; tetrahydrofuran / 2 h / Ambient temperature 2: pyridine / benzene / 2 h / Ambient temperature 3: H2O / 1.5 h / Heating 4: 2.) Ag2CO3 / 1.) toluene, 3 d, room temp., 2.) methanol, 1.5 h reflux View Scheme

1: pyridine / benzene / 2 h / Ambient temperature 2: H2O / 1.5 h / Heating 3: 2.) Ag2CO3 / 1.) toluene, 3 d, room temp., 2.) methanol, 1.5 h reflux View Scheme

silver carbonate 1.) toluene, 3 d, room temp., 2.) methanol, 1.5 h reflux;