toluene-4-sulfonic acid in methanol

methanol; DOWEX 50 W-X2 cation exchange resin T=40°C; 2 h;

methanol; DOWEX 50 W-X2 cation exchange resin T=40°C; 2 h;

1: 88 percent / p-toluenesulfonic acid / methanol 2: 10percent Pd/BaSO4 / methanol / 760 Torr / Ambient temperature View Scheme

carbon tetrabromide; triphenylphosphine in dichloromethane 0 deg C to room temp. overnight;

1: TsOH / methanol / Heating 2: H2 / Lindlar catalyst / hexane View Scheme

1.1: PTS / methanol / 20 h / 20 °C 2.1: 8.84 g / PBr3; pyridine / diethyl ether / 6 h / 20 °C 3.1: EtMgBr / tetrahydrofuran / 3 h / 40 °C 3.2: CuCN / tetrahydrofuran / 18 h / 20 °C 4.1: 0.93 g / PTS / methanol / 20 h / 20 °C 5.1: 88 percent / H2; quinoline / Pd/BaSO4 / ethanol 6.1: 65 percent / Dess-Martin periodinane / CH2Cl2 / 3 h / 20 °C View Scheme