sulfuric acid; acetic acid 24 h; Heating; Yield given;

1: aq. H2SO4, CH3COOH / 24 h / Heating 2: 82 percent / n-butyllithium / hexane; diethyl ether / 0.5 h / 0 °C View Scheme

1: aq. H2SO4, CH3COOH / 24 h / Heating 2: 82 percent / n-butyllithium / hexane; diethyl ether / 0.5 h / 0 °C 3: 75 percent / sodium borohydride / methanol / 1 h / Ambient temperature 4: 100 percent / SOCl2 / toluene / 1.) RT, 30 min, 2.) from 50 deg C to 55 deg C, 1 h View Scheme