1: iPr2NEt / CH2Cl2 / 0.5 h / -78 °C 2: 1) mCPBA, KHCO3, 2) citric acid / 1) CH2Cl2, -30 to -20 deg C, 1 h, 2) MeOH, 0 deg C to RT 3: NaIO4 / methanol; H2O / 0 deg C, 12 h; RT, 3 h 4: CHCl3 / Ambient temperature 5: 71 percent / LTBA / tetrahydrofuran / -78 to -40 deg C; -35 deg C, 4 h 6: 89 percent / nBu3P / tetrahydrofuran / 1 h / 0 - 20 °C 7: 85 percent / 30percent H2O2 / tetrahydrofuran / 18 h / 0 - 20 °C 8: I2, NaHCO3 / CH2Cl2 / 48 h / Ambient temperature 9: 90 percent / methanol / 4 h / 0 - 20 °C 10: LTBA / tetrahydrofuran / 3 h / 0 °C 11: pyridine / 2 h / 0 - 20 °C 12: 56 percent / CSA, dihydroquinone / benzene / 3 h / Heating 13: 1) mCPBA, 2) 2N HCl / 1) CH2Cl2, -30 to -25 deg C, 20 h, 2) THF, RT, 16 h 14: Me4NBH(OAc)3 / acetic acid; acetonitrile / 2 h / 0 °C 15: DDQ / dioxane / 4 h / 80 °C 16: 94 percent / Ag2O / acetonitrile / 24 h / Ambient temperature 17: 92 percent / MsCl, Et3N / CH2Cl2 / Ambient temperature 18: 47 percent / OsO4, DABCO / tetrahydrofuran / 24 h / -40 °C 19: 92 percent / pyridinium p-toluenesulfonate / CH2Cl2 / 16 h / Ambient temperature 20: CH(NMe2)3 / 1 h / 100 °C 21: 2N HCl / tetrahydrofuran / 20 h / Ambient temperature 22: PCC / CH2Cl2 / 5 h / Ambient temperature 23: CH2Cl2 / 0.33 h / Ambient temperature 24: DBN / CH2Cl2 / 6 h / Ambient temperature 25: K2CO3, MeOH / 5 h / Ambient temperature 26: 1N HCl / tetrahydrofuran / 12 h / Ambient temperature 27: 49 percent / pyridine / 12 h / -20 °C 28: 73 percent / PCC / CH2Cl2 / 2 h / Ambient temperature View Scheme

1: iPr2NEt / CH2Cl2 / 0.5 h / -78 °C 2: 1) mCPBA, KHCO3, 2) citric acid / 1) CH2Cl2, -30 to -20 deg C, 1 h, 2) MeOH, 0 deg C to RT 3: NaIO4 / methanol; H2O / 0 deg C, 12 h; RT, 3 h 4: CHCl3 / Ambient temperature 5: 71 percent / LTBA / tetrahydrofuran / -78 to -40 deg C; -35 deg C, 4 h 6: 89 percent / nBu3P / tetrahydrofuran / 1 h / 0 - 20 °C 7: 85 percent / 30percent H2O2 / tetrahydrofuran / 18 h / 0 - 20 °C 8: I2, NaHCO3 / CH2Cl2 / 48 h / Ambient temperature 9: 90 percent / methanol / 4 h / 0 - 20 °C 10: LTBA / tetrahydrofuran / 3 h / 0 °C 11: pyridine / 2 h / 0 - 20 °C 12: 56 percent / CSA, dihydroquinone / benzene / 3 h / Heating 13: 1) mCPBA, 2) 2N HCl / 1) CH2Cl2, -30 to -25 deg C, 20 h, 2) THF, RT, 16 h 14: Me4NBH(OAc)3 / acetic acid; acetonitrile / 2 h / 0 °C 15: DDQ / dioxane / 4 h / 80 °C 16: 94 percent / Ag2O / acetonitrile / 24 h / Ambient temperature 17: 92 percent / MsCl, Et3N / CH2Cl2 / Ambient temperature 18: 47 percent / OsO4, DABCO / tetrahydrofuran / 24 h / -40 °C 19: 92 percent / pyridinium p-toluenesulfonate / CH2Cl2 / 16 h / Ambient temperature 20: CH(NMe2)3 / 1 h / 100 °C 21: 2N HCl / tetrahydrofuran / 20 h / Ambient temperature 22: PCC / CH2Cl2 / 5 h / Ambient temperature 23: CH2Cl2 / 0.33 h / Ambient temperature 24: DBN / CH2Cl2 / 6 h / Ambient temperature 25: K2CO3, MeOH / 5 h / Ambient temperature 26: 1N HCl / tetrahydrofuran / 12 h / Ambient temperature 27: 49 percent / pyridine / 12 h / -20 °C View Scheme