1: 96 percent / BBr3 / CH2Cl2 / 1.) -78 deg C, 1 h, 2.) RT, 2 h 2: 94 percent / Adogen 464, potassium nitrosodisulfonate, 1/6 M KH2PO4 / benzene; H2O / 2 h / Ambient temperature 3: 1.) KBH4, 2.) pyridine / 1.) ethanol, 21 h, 2.) 0 deg C, overnight 4: 84 percent / ammonia, methanol / 96 h / Ambient temperature View Scheme

boron tribromide in dichloromethane 1.) -78 deg C, 1 h, 2.) RT, 2 h;