1: diethyl ether / 1) 0 deg C, 1 h, 2) RT, 3 h 2: NaOMe / methanol / 0.5 h / 25 °C 3: 1) pyridine, 2) silica gel 60 / 1) 0 deg C to RT, 2) xylene, 50 deg C then reflux, 45 min View Scheme