1: 76 percent / 1.6 M BuLi / hexane; tetrahydrofuran 2: 1.) 1.6 M BuLi / 1.) THF, hexane, -78 deg C; to RT, overnight; 2.) THF, hexane, 5 min, -78 deg C View Scheme

n-butyllithium 1.) THF, hexane, -78 deg C; to RT, overnight; 2.) THF, hexane, 5 min, -78 deg C; Yield given. Multistep reaction;