1.1: n-butyllithium / tetrahydrofuran; hexane / -80 °C / |Inert atmosphere 1.2: 2.33 h / -80 - 20 °C / |Inert atmosphere 2.1: ammonium hydroxide / methanol / 1 h 3.1: phosphorous pentoxide / 1.5 h / 110 - 150 °C View Scheme