boron tribromide in dichloromethane

1: Fe, HCl / ethanol 2: NaHCO3 / dimethylformamide 3: 1) t-BuLi, Cp2Zr(CH3)Cl, 2) I2 / 1) THF, -78 to 45 deg C, 2) CH2Cl2, 0 deg C 4: 86 percent / BBr3 / CH2Cl2 View Scheme

1: NaHCO3 / dimethylformamide 2: 1) t-BuLi, Cp2Zr(CH3)Cl, 2) I2 / 1) THF, -78 to 45 deg C, 2) CH2Cl2, 0 deg C 3: 86 percent / BBr3 / CH2Cl2 View Scheme

1: 1) t-BuLi, Cp2Zr(CH3)Cl, 2) I2 / 1) THF, -78 to 45 deg C, 2) CH2Cl2, 0 deg C 2: 86 percent / BBr3 / CH2Cl2 View Scheme

1: 88 percent / CuBr2, t-BuONO / acetonitrile 2: Fe, HCl / ethanol 3: NaHCO3 / dimethylformamide 4: 1) t-BuLi, Cp2Zr(CH3)Cl, 2) I2 / 1) THF, -78 to 45 deg C, 2) CH2Cl2, 0 deg C 5: 86 percent / BBr3 / CH2Cl2 View Scheme