1.1: n-BuLi / tetrahydrofuran; hexane / 1 h / 0 °C 1.2: 87 percent / tetrahydrofuran; hexane / 1.5 h / 0 °C 2.1: 72 percent / LiNbMoO6; aq. H2O2 / methanol; benzene / 6 h / 25 °C 3.1: t-BuOK / dimethylformamide / 1 h / -20 °C 3.2: 85 percent / dimethylformamide / 3 h / -20 °C 4.1: 82 percent / NaOH / ethanol / 15 h / Heating View Scheme