1: 97 percent / diethyl ether / 0.5 h / 0 °C 2: 54 percent / bromine / acetic acid / 2 h / Ambient temperature 3: 20 percent / 1,5-diazabicyclo<5.4.0>undec-5-ene / benzene / 0.75 h 4: 1) boron tribromide, 2) conc. aq. hydrochloric acid / 1) dichloromethane, reflux, 30 min, 2) 30 min 5: 82 percent / sodium methoxide / methanol / 0.5 h View Scheme