1: in diethyl ether T=-78 - 0°C; 2: With ammonium chloride in diethyl ether T=0°C; 0.166667 h;

1.1: tetrahydrofuran / 12 h / 0 - 20 °C 2.1: TBAF / tetrahydrofuran / 6 h 3.1: Et3N / CH2Cl2 / 0 - 20 °C 4.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 5.1: diethyl ether / -78 - 0 °C 5.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme

1.1: HIO4*2H2O / diethyl ether; tetrahydrofuran / 0.5 h / 0 °C 2.1: NaBH4 / ethanol / 1 h / 0 °C 3.1: imidazole / dimethylformamide / 0 °C 4.1: K2CO3 / methanol / 1 h / 20 °C 5.1: 90 percent / Et3N / hexane / 24 h / 0 - 20 °C 6.1: tetrahydrofuran / 12 h / 0 - 20 °C 7.1: TBAF / tetrahydrofuran / 6 h 8.1: Et3N / CH2Cl2 / 0 - 20 °C 9.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 10.1: diethyl ether / -78 - 0 °C 10.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme

1.1: 100 percent / mCPBA / CH2Cl2 / 2 h / -20 - 20 °C 2.1: HIO4*2H2O / diethyl ether; tetrahydrofuran / 0.5 h / 0 °C 3.1: NaBH4 / ethanol / 1 h / 0 °C 4.1: imidazole / dimethylformamide / 0 °C 5.1: K2CO3 / methanol / 1 h / 20 °C 6.1: 90 percent / Et3N / hexane / 24 h / 0 - 20 °C 7.1: tetrahydrofuran / 12 h / 0 - 20 °C 8.1: TBAF / tetrahydrofuran / 6 h 9.1: Et3N / CH2Cl2 / 0 - 20 °C 10.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 11.1: diethyl ether / -78 - 0 °C 11.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme

1.1: NaBH4 / ethanol / 1 h / 0 °C 2.1: imidazole / dimethylformamide / 0 °C 3.1: K2CO3 / methanol / 1 h / 20 °C 4.1: 90 percent / Et3N / hexane / 24 h / 0 - 20 °C 5.1: tetrahydrofuran / 12 h / 0 - 20 °C 6.1: TBAF / tetrahydrofuran / 6 h 7.1: Et3N / CH2Cl2 / 0 - 20 °C 8.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 9.1: diethyl ether / -78 - 0 °C 9.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme

1.1: imidazole / dimethylformamide / 0 °C 2.1: K2CO3 / methanol / 1 h / 20 °C 3.1: 90 percent / Et3N / hexane / 24 h / 0 - 20 °C 4.1: tetrahydrofuran / 12 h / 0 - 20 °C 5.1: TBAF / tetrahydrofuran / 6 h 6.1: Et3N / CH2Cl2 / 0 - 20 °C 7.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 8.1: diethyl ether / -78 - 0 °C 8.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme

1.1: Et3N / CH2Cl2 / 0 - 20 °C 2.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 3.1: diethyl ether / -78 - 0 °C 3.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme

1.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 2.1: diethyl ether / -78 - 0 °C 2.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme

1.1: 90 percent / Et3N / hexane / 24 h / 0 - 20 °C 2.1: tetrahydrofuran / 12 h / 0 - 20 °C 3.1: TBAF / tetrahydrofuran / 6 h 4.1: Et3N / CH2Cl2 / 0 - 20 °C 5.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 6.1: diethyl ether / -78 - 0 °C 6.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme

1.1: K2CO3 / methanol / 1 h / 20 °C 2.1: 90 percent / Et3N / hexane / 24 h / 0 - 20 °C 3.1: tetrahydrofuran / 12 h / 0 - 20 °C 4.1: TBAF / tetrahydrofuran / 6 h 5.1: Et3N / CH2Cl2 / 0 - 20 °C 6.1: 18-crown-6 / CH2Cl2 / 6 h / Heating 7.1: diethyl ether / -78 - 0 °C 7.2: aq. NH4Cl / diethyl ether / 0.17 h / 0 °C View Scheme