1: DIBAH / toluene / 2 h / -78 °C 2: 91 percent / tetrahydrofuran / 5 h / Ambient temperature 3: 91 percent / Et3N, DMAP / CH2Cl2 / 3 h / Ambient temperature 4: 76 percent / CuI*P(OEt)3 / tetrahydrofuran / -40 deg C then 0 deg C, 2 h 5: TBAF / tetrahydrofuran / 3 h / Ambient temperature 6: K2CO3 / methanol / 5 h / Ambient temperature 7: pyridinium dichromate / CH2Cl2 / 24 h / Ambient temperature 8: pyridinium dichromate / dimethylformamide / 24 h / Ambient temperature 9: 67 percent / AcOH, H2O / tetrahydrofuran / 14 h / 40 °C View Scheme

1: DIBAH / toluene / 2 h / -78 °C 2: 91 percent / tetrahydrofuran / 5 h / Ambient temperature 3: 91 percent / Et3N, DMAP / CH2Cl2 / 3 h / Ambient temperature 4: 76 percent / CuI*P(OEt)3 / tetrahydrofuran / -40 deg C then 0 deg C, 2 h 5: TBAF / tetrahydrofuran / 3 h / Ambient temperature 6: K2CO3 / methanol / 5 h / Ambient temperature 7: pyridinium dichromate / CH2Cl2 / 24 h / Ambient temperature 8: pyridinium dichromate / dimethylformamide / 24 h / Ambient temperature 9: 67 percent / AcOH, H2O / tetrahydrofuran / 14 h / 40 °C View Scheme

1: 79 percent / diisobutylaluminum hydride / toluene; hexane / 0.33 h 2: 1.) sodium methylsulfinylcarbanide / 1.) Me2SO, 2.) Me2SO, 2 h 3: Jones reagent / acetone / 0.08 h / -20 °C 4: 43 percent / 65percent aq. acetic acid / 14 h View Scheme