1: 1.) O3, O2, 2.) Me2S, 3.) Na2SO4, TsOH*H2O / 1.) CH2Cl2, MeOH, -65 deg C, 2.) -60 deg C, 1h; -15 deg C, 1 h; 0 deg C, 1 h; 20 deg C, 12 h, 3.) benzene, reflux, 1 h 2: 2.) 10percent H2SO4 / 1.) ether, -10 deg C, 3 h, 2.) 1h View Scheme

dimethylsulfide; oxygen; toluene-4-sulfonic acid; ozone; sodium sulfate 1.) CH2Cl2, MeOH, -65 deg C, 2.) -60 deg C, 1h; -15 deg C, 1 h; 0 deg C, 1 h; 20 deg C, 12 h, 3.) benzene, reflux, 1 h; Yield given. Multistep reaction;