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

1: benzene / 1.) RT, 1 h, 2.) reflux, 24 h 2: CrO3, 20percent aq. H2SO4 / acetone / 4 h / Ambient temperature View Scheme

sodium hydroxide; sodium dithionite 1) THF/CH3OH, 10 min.; 2) H20, 12 h, room temp.; Yield given. Multistep reaction;

1: 93 percent / K2CO3 / acetone / 5 h / Heating 2: 97 percent / 2 N NaOH / ethanol / 5 h 3: 1) Na2S2O4, 0.3 N NaOH / 1) THF/CH3OH, 10 min.; 2) H20, 12 h, room temp. View Scheme

1: 1) B2O3, H2SO4 (conc.); 2) ice water / 1) 3 h, 110 deg C; 2) 3 h 2: 93 percent / K2CO3 / acetone / 5 h / Heating 3: 97 percent / 2 N NaOH / ethanol / 5 h 4: 1) Na2S2O4, 0.3 N NaOH / 1) THF/CH3OH, 10 min.; 2) H20, 12 h, room temp. View Scheme

1: 97 percent / 2 N NaOH / ethanol / 5 h 2: 1) Na2S2O4, 0.3 N NaOH / 1) THF/CH3OH, 10 min.; 2) H20, 12 h, room temp. View Scheme