1: 95 percent / L-Selectride / tetrahydrofuran / 2.5 h / -78 - 0 °C 2: 1.) BH3, 2.) 30percent aq. H2O2, aq. NaOH / 1.) THF, 0 deg C to RT, 1.5 h, 2.) THF, water, overnight 3: 48 percent / p-toluenesulfonic acid / toluene / 2 h / 80 °C View Scheme