1.1: 90 percent / ammonium molybdate; aq. H2O2 / aq. ethanol / 12 h / 0 - 20 °C 2.1: n-BuLi / tetrahydrofuran / -78 °C 2.2: 74 percent / tetrahydrofuran / -78 - 20 °C 3.1: conc. H2SO4 / methanol / 20 °C View Scheme