1: 89 percent / diethyl azodicarboxylate; PPh3 / benzene; toluene / 0.5 h / 20 °C 2: TFA / CH2Cl2 / 0.25 h / 20 °C 3: pyrrolidine / methanol; acetonitrile / 0.08 h / 20 °C 4: pyrrolidine / methanol; acetonitrile / 4 h / Heating 5: 88 percent / PPh3 / CCl4; acetonitrile / 0.5 h / 70 °C 6: KOH / methanol / 0.75 h / 80 °C View Scheme

1.1: 89 percent / diethyl azodicarboxylate; PPh3 / benzene; toluene / 0.5 h / 20 °C 2.1: TFA / CH2Cl2 / 0.25 h / 20 °C 3.1: pyrrolidine / methanol; acetonitrile / 0.08 h / 20 °C 4.1: pyrrolidine / methanol; acetonitrile / 4 h / Heating 5.1: 88 percent / PPh3 / CCl4; acetonitrile / 0.5 h / 70 °C 6.1: KOH / methanol / 0.75 h / 80 °C 7.1: t-BuOK / tetrahydrofuran; 2-methyl-propan-2-ol / 1.5 h / 0 °C 8.1: 88 percent / (PhSeO)2O / benzene / 0.5 h / 80 °C 9.1: MCPBA; NaHCO3; H2O / methanol; CH2Cl2 / 0.08 h / 0 °C 10.1: NaBH3CN; aq. HCl / methanol; CH2Cl2 / 0.58 h / 0 - 20 °C / pH 3.0 10.2: NaHSO3; Na2CO3 / aq. methanol; CH2Cl2 / 0.5 h / 20 °C / pH 9 - 10 11.1: 91 percent / AcONa / 4 h / 20 °C View Scheme

1.1: 89 percent / diethyl azodicarboxylate; PPh3 / benzene; toluene / 0.5 h / 20 °C 2.1: TFA / CH2Cl2 / 0.25 h / 20 °C 3.1: pyrrolidine / methanol; acetonitrile / 0.08 h / 20 °C 4.1: pyrrolidine / methanol; acetonitrile / 4 h / Heating 5.1: 88 percent / PPh3 / CCl4; acetonitrile / 0.5 h / 70 °C 6.1: KOH / methanol / 0.75 h / 80 °C 7.1: t-BuOK / tetrahydrofuran; 2-methyl-propan-2-ol / 1.5 h / 0 °C 8.1: 88 percent / (PhSeO)2O / benzene / 0.5 h / 80 °C 9.1: MCPBA; NaHCO3; H2O / methanol; CH2Cl2 / 0.08 h / 0 °C 10.1: NaBH3CN; aq. HCl / methanol; CH2Cl2 / 0.58 h / 0 - 20 °C / pH 3.0 10.2: NaHSO3; Na2CO3 / aq. methanol; CH2Cl2 / 0.5 h / 20 °C / pH 9 - 10 View Scheme