1: 1.) n-BuLi / 1.) THF, hexane, a) 0 deg C, 2.5 h, b) reflux, 0.5 h, 2.) THF, hexane, a) RT, 0.5 h, b) reflux, 17 h 2: 97 percent / BBr3 / CH2Cl2 / 24 h / Ambient temperature 3: 97 percent / Ag2O, Na2SO4 / diethyl ether / 0.07 h 4: 32 percent / CH2Cl2 / 0.07 h 5: aq. sodium dithionite View Scheme

1: 1.) n-BuLi / 1.) THF, hexane, a) 0 deg C, 2.5 h, b) reflux, 0.5 h, 2.) THF, hexane, a) RT, 0.5 h, b) reflux, 17 h 2: 97 percent / BBr3 / CH2Cl2 / 24 h / Ambient temperature 3: 97 percent / Ag2O, Na2SO4 / diethyl ether / 0.07 h 4: 32 percent / CH2Cl2 / 0.07 h 5: aq. sodium dithionite View Scheme

1: 97 percent / Ag2O, Na2SO4 / diethyl ether / 0.07 h 2: 32 percent / CH2Cl2 / 0.07 h 3: aq. sodium dithionite View Scheme

1: 97 percent / BBr3 / CH2Cl2 / 24 h / Ambient temperature 2: 97 percent / Ag2O, Na2SO4 / diethyl ether / 0.07 h 3: 32 percent / CH2Cl2 / 0.07 h 4: aq. sodium dithionite View Scheme

1: 32 percent / CH2Cl2 / 0.07 h 2: aq. sodium dithionite View Scheme

sodium dithionite