1: 1.) diethylmethoxyborane, 2.) sodium borohydride / 1.) THF, methanol, -78 deg C, 10 min, 2.) THF, methanol, -78 deg C, 3 h 2: 81 percent / TBAF / tetrahydrofuran / 2 h / 0 °C 3: p-toluenesulfonic acid / 2 h / Ambient temperature 4: t-Bu3P*Pt(CH2=CHSiMe2)2O / 1 h / Ambient temperature 5: 80 percent / (η3-allylPdCl)2, TBAF / tetrahydrofuran / 0.5 h / 60 °C View Scheme