1: KOH / dimethylsulfoxide / 4 h / Ambient temperature 2: 77 percent / H2SO4 / H2O / 2 h / Heating 3: 1.) n-BuLi / 1.) ether/hexane; 2.) ether, 20 deg C, 15 h View Scheme

1: 77 percent / H2SO4 / H2O / 2 h / Heating 2: 1.) n-BuLi / 1.) ether/hexane; 2.) ether, 20 deg C, 15 h View Scheme

n-butyllithium 1.) ether/hexane; 2.) ether, 20 deg C, 15 h; Yield given. Multistep reaction;