1: 1) Mg / 1) ether, 2) 0 deg C, 15 min 2: 90 percent / p-toluenesulphonic acid / methanol / 4 h / Heating View Scheme

1: 1) Mg / 1) ether, 2) 0 deg C, 15 min 2: 90 percent / p-toluenesulphonic acid / methanol / 4 h / Heating 3: 92 percent / pyridinium chlorochromate / CH2Cl2 / 4 h / Ambient temperature View Scheme

1.1: Mg / diethyl ether 1.2: 90 percent / diethyl ether / 2.5 h / Heating 2.1: 85 percent / TsOH / methanol / 4 h / Heating 3.1: 0.5 g / Ag2CO3 / methanol; benzene / 6 h / Heating View Scheme