1: 1.) triethyloxonium tetrafluoroborate, 2.) sodium cyanoborohydride / 1.) CH2Cl2, RT, 12 h, 2.) methanol, RT, 1 h 2: 1.) LDA, 2.) oxygen / 1.) THF, hexane, from -78 deg C to 0 deg C, 2 h 10 min, 2a.) -78 deg C, 15 min, 2b.) RT, 15 min 3: LiAlH4 / tetrahydrofuran / 1 h / Ambient temperature 4: sodium periodate / methanol; H2O / 0.67 h / Ambient temperature 5: sodium, liquid ammonia / tetrahydrofuran; methanol; H2O / 0.5 h / -78 °C 6: 95 percent / 6 M aq. HCl / 0.5 h / 65 - 70 °C View Scheme