1.1: 70 percent / tBuLi / pentane; tetrahydrofuran / 0.5 h / -100 - 0 °C 2.1: 84 percent / TFA; anisole / 24 h / Heating 3.1: nBuLi / tetrahydrofuran; hexane / 0.5 h / -78 - 20 °C 3.2: 80 percent / tetrahydrofuran; hexane / 2.17 h / -78 - 20 °C 4.1: 62 percent / tBuLi / pentane; tetrahydrofuran / 0.5 h / -100 - 20 °C 5.1: 92 percent / triethylsilyl hydride; TFA / CH2Cl2 / 2 h / 20 °C View Scheme

1: 70 percent / tBuLi / pentane; tetrahydrofuran / 0.5 h / -100 - 0 °C 2: 84 percent / TFA; anisole / 24 h / Heating View Scheme