1.1: n-butyllithium / hexane; tetrahydrofuran / 3 h / 0 - 20 °C 1.2: 96 percent / potassium hydroxide / methanol / 0.25 h / 0 - 20 °C 2.1: 82 percent / acidic alumina / toluene / 1.5 h / Heating View Scheme