1: 100 percent / HBr / acetic acid / 16 h / Ambient temperature 2: 1.) 5percent NaOH, Na2S2O4 / 1.) MeOH, water, 70 deg C, 15 min, 2.) MeOH, water, 90 deg C, overnight View Scheme

sodium hydroxide; sodium dithionite 1.) MeOH, water, 70 deg C, 15 min, 2.) MeOH, water, 90 deg C, overnight; Yield given. Multistep reaction;