1.1: 66 percent / N-methylmorpholine N-oxide; tetrapropylammonium perruthenate / CH2Cl2 / 1.5 h / 0 °C 2.1: n-BuLi / tetrahydrofuran; toluene / 0.17 h / 0 °C 2.2: 90 percent / tetrahydrofuran; toluene / 1 h / -20 °C View Scheme