1: 1.) Mg / 1.) diethyl ether, 30 min, 2.) THF, diethyl ether, overnight, reflux 2: CrO3, conc. H2SO4 / acetone; H2O 3: 85 percent / conc. HCl / H2O / 1 h / Heating View Scheme

1: in tetrahydrofuran T=60°C; 2: With chromium(VI) oxide; sulfuric acid in water; acetone T=21°C; 0.25 h;

1: 1.) Mg / 1.) diethyl ether, 30 min, 2.) THF, diethyl ether, overnight, reflux 2: CrO3, conc. H2SO4 / acetone; H2O View Scheme

1: 1.) Mg / 1.) diethyl ether, 30 min, 2.) THF, diethyl ether, overnight, reflux 2: CrO3, conc. H2SO4 / acetone; H2O 3: 85 percent / conc. HCl / H2O / 1 h / Heating 4: 64.4 percent / I2, HgO / acetic acid / 1 h / Ambient temperature View Scheme

1: 1.) Mg / 1.) diethyl ether, 30 min, 2.) THF, diethyl ether, overnight, reflux 2: CrO3, conc. H2SO4 / acetone; H2O 3: 85 percent / conc. HCl / H2O / 1 h / Heating 4: Br2 / acetic acid View Scheme