1: 94 percent / CrO3, H2SO4 / H2O; acetone / 1.5 h / Ambient temperature 2: 1.) PPh3, 2.) NaBH3CN / 1.) THF, rt, 12 h, 2.) MeOH, AcOH, 12 h 3: 42 percent / H2O; formic acid / 12 h / 120 °C View Scheme