trifluoroacetic acid in dichloromethane T=20°C;

1: 1 M LiBEt3H, 30percent H2O2 / tetrahydrofuran / 1.) -78 deg C, 30 min; 2.) 0 deg C, 20 min 2: p-TsOH*H2O / Ambient temperature 3: 1.) CuBr*Me2S, 2.) BF3*OEt2 / 1.) ether, -40 deg C, 45 min, 2.) -78 deg C, 30 min; 15 min; -78 deg C to room temp., 3 h; room temp., 1 h 4: TFA / CH2Cl2 / Ambient temperature View Scheme

1: p-TsOH*H2O / Ambient temperature 2: 1.) CuBr*Me2S, 2.) BF3*OEt2 / 1.) ether, -40 deg C, 45 min, 2.) -78 deg C, 30 min; 15 min; -78 deg C to room temp., 3 h; room temp., 1 h 3: TFA / CH2Cl2 / Ambient temperature View Scheme

1: 1.) CuBr*Me2S, 2.) BF3*OEt2 / 1.) ether, -40 deg C, 45 min, 2.) -78 deg C, 30 min; 15 min; -78 deg C to room temp., 3 h; room temp., 1 h 2: TFA / CH2Cl2 / Ambient temperature View Scheme

hydrogenchloride; water; sodium cyanoborohydride in isopropyl alcohol 2 h; Ambient temperature; Yield givenYields of byproduct given. Title compound not separated from byproducts;