1: 1.) n-BuLi, 2.) MgBr / 1.) hexane, THF, -78 deg C, 5 min, 2.) ether, benzene, from -78 deg C to RT, 1.5 h 2: 86 percent / aq. HCl / tetrahydrofuran / 2 h / Heating View Scheme

With  n-butyllithium; magnesium bromide  1.) hexane, THF, -78 deg C, 5 min, 2.) ether, benzene, from -78 deg C to RT, 1.5 h;  Yield given. Multistep reaction;