1: 86 percent / DMAP; Et3N / CH2Cl2 / 20 °C 2: 45 percent Chromat. / TBAF*3H2O / tetrahydrofuran / 0.08 h / 20 °C View Scheme

1: 83 percent / DMAP / CH2Cl2 2: 74 percent / i-Pr2NLi / tetrahydrofuran / -78 °C 3: 90 percent / H2O2, pyridine / CH2Cl2 / -78 to 0 deg C View Scheme

1.1: 4-(N,N-dimethlyamino)pyridine; triethylamine / dichloromethane / 18.16 h / 24 °C 2.1: lithium triethylborohydride / toluene; tetrahydrofuran / 1.08 h / -50 - -45 °C 2.2: 14.42 h / -50 - 20 °C 2.3: 0.08 h / Cooling with ice/water 3.1: diethylzinc / toluene / 0.25 h / -30 °C 3.2: 19.66 h / -25 - -21 °C 3.3: 0.33 h / -25 - 20 °C 4.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 4.83 h / 20 °C 5.1: sodium periodate; ruthenium trichloride / tetrachloromethane; acetonitrile; water / 1.25 h View Scheme

1.1: Lawesson's reagent / tetrahydrofuran / 2 h / 20 °C 2.1: CH2Cl2 / 5 h / 20 °C 3.1: NH4Cl / methanol / 3.5 h / 50 °C 4.1: ethyl acetate / 16 h / 20 °C 5.1: HBr; AcOH / aq. ethanol / 5.5 h / Heating 6.1: TBAF / tetrahydrofuran / 1 h / 0 - 20 °C 7.1: 99 percent / aq. NaOH; n-Bu4NHSO4 / 12 h / 20 °C 8.1: n-BuLi / tetrahydrofuran / 0.5 h / -78 °C 8.2: Bu3SnI 8.3: 48 percent / Pd(PPh3)4 / dimethylformamide / 96 h / 80 °C 9.1: H2O2; AcOH / 48 h 9.2: 36 percent / 20 °C View Scheme