potassium carbonate in dimethyl sulfoxide T=80°C; 1 h;

1: LDA / tetrahydrofuran / 0.75 h / -78 - -30 °C 2: 2) H3O+ 3: 82 percent / NEt3 / CH2Cl2 / 1) 0 deg C, 30 min 2) r.t., 5 h 4: 53 percent / K2CO3 / dimethylsulfoxide / 1 h / 80 °C View Scheme

1: 82 percent / NEt3 / CH2Cl2 / 1) 0 deg C, 30 min 2) r.t., 5 h 2: 53 percent / K2CO3 / dimethylsulfoxide / 1 h / 80 °C View Scheme