1: 75 percent / 1.) LiHMDS, HMPA; 2.) AcOH / tetrahydrofuran / -78 °C 2: 71 percent / H2 / Pd-CaCO3 3: 65 percent / Et3SiH, CF3CO2H / benzene; CH2Cl2 4: 80 percent / BBr3 / CH2Cl2 / 0 °C View Scheme

1: 75 percent / 1.) LiHMDS, HMPA; 2.) AcOH / tetrahydrofuran / -78 °C 2: 71 percent / H2 / Pd-CaCO3 3: 65 percent / Et3SiH, CF3CO2H / benzene; CH2Cl2 View Scheme

1: With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 1 h; Inert atmosphere; 2: With acetic acid in tetrahydrofuran T=-78 - 20°C;