1: 1.) disiamylborane, 2.) H2O2 / 1.) THF, 0 deg C, then 25 deg C, 0.5 h, 2.) 0 deg C, aq. NaOH, 50 deg C, 1 h 2: Jones reagent / acetone / 0.17 h / 25 °C 3: 98 percent / trimethyl iodide / CHCl3 / 15 h / 60 °C View Scheme