1: 1) 1.6M n-BuLi / 1) hexane, THF, RT, 1 h, 2) THF, overnight, RT 2: 1) 1.6M n-BuLi / 1) hexane, THF, RT, 0.5 h, 2) THF, 3 h, RT 3: KF, 18-crown-6 / tetrahydrofuran / 4 h / Ambient temperature View Scheme

1: 1) 1.6M n-BuLi / 1) hexane, THF, RT, 0.5 h, 2) THF, 3 h, RT 2: KF, 18-crown-6 / tetrahydrofuran / 4 h / Ambient temperature View Scheme

potassium fluoride; 18-crown-6 ether in tetrahydrofuran 4 h; Ambient temperature; Title compound not separated from byproducts;