in diethyl ether

1: With ozone in methanol; dichloromethane T=-78°C; 2: With dimethylsulfide in methanol; dichloromethane T=25°C; 4 h;

1.1: 87 percent / Dess-Martin periodinane / CH2Cl2 / 2 h / 25 °C 2.1: O3 / CH2Cl2; methanol / -78 °C 2.2: Me2S / CH2Cl2; methanol / 4 h / 25 °C View Scheme

1: 1) NaH / 1) THF, 25 deg C, 15 min, 2) THF, 25 deg C, 1 h 2: 99 percent / trifluoroacetic acid / CH2Cl2 / 0.5 h / 25 °C View Scheme

1: 74 percent / diethyl ether / 0.5 h / -100 °C 2: 98 percent / 2,6-lutidine / CH2Cl2 / 0.75 h / -78 °C 3: 1) O3, 2) PPh3 / 1) CH2Cl2, -78 deg C, 30 min, 2) Ch2Cl2, -78 deg C -> room temperature; room temperature, 1 h 4: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran / 1) -78 deg C, 5 min, 2) 0 deg C, 15 min 5: 1.26 g / Et3N, 4-DMAP / CH2Cl2 / 1) 0 deg C, 2 h, 2) 25 deg C, 10 h 6: 1) LDA / 1) THF, -78 deg C, 15 min; -78 deg C -> -40 deg C, 1 h, 2) THF, -78 deg C, 15 min 7: 96 percent / 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 8: 85 percent / camphorsulfonic acid / CH2Cl2; methanol / 0.5 h / 0 - 25 °C View Scheme

1: 74 percent / diethyl ether / 0.5 h / -100 °C 2: 98 percent / 2,6-lutidine / CH2Cl2 / 0.75 h / -78 °C 3: 1) O3, 2) PPh3 / 1) CH2Cl2, -78 deg C, 30 min, 2) Ch2Cl2, -78 deg C -> room temperature; room temperature, 1 h 4: 93 percent / NaClO2, 2-methyl-2-butene, NaH2PO4 / 2-methyl-propan-2-ol; tetrahydrofuran; H2O / 4 h / Ambient temperature 5: 1) LDA / 1) THF, -78 deg C, 15 min; -40 deg C, 0.5 h, 2) THF, -78 deg C, 15 min 6: 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 7: 1.1 g / K2CO3 / methanol / 0.25 h / 25 °C 8: 78 percent / TBAF / tetrahydrofuran / 8 h / 25 °C 9: 1) Et3N, 2,4,6-trichlorobenzoyl chloride, 2) 4-DMAP / 1) THF, 0 deg C, 15 min, 2) toluene, 25 deg C, 0.5 h 10: 92 percent / CF3CO2H / CH2Cl2 / 1) -20 deg C -> 0 deg C, 2) 0 deg C, 1 h 11: 65 percent / Na2EDTA, 1,1,1-trifluoroacetone, Oxone, NaHCO3 / acetonitrile; H2O / 0 °C View Scheme

1.1: 88 percent / Bu2BOTf; DIPEA / CH2Cl2 / 1 h / -78 °C 2.1: 95 percent / 2,6-lutidine / CH2Cl2 / 1 h / 0 °C 3.1: 76 percent / lithium hydroxide; hydrogen peroxide / tetrahydrofuran; H2O / 4 h / 20 °C 4.1: diisopropylamine; n-butyllithium / tetrahydrofuran; hexane / 1.25 h / -78 - -40 °C 4.2: 59 percent / ZnCl2 / tetrahydrofuran; hexane; diethyl ether / 0.25 h / -78 °C 5.1: pyridine / CH2Cl2 / 1 h / 0 °C 6.1: CH2Cl2 / 5 h / 20 °C 7.1: 0.67 g / acetic acid / tetrahydrofuran; H2O / 3 h / 0 °C 8.1: 72 percent / magnesium bromide; nitromethane; 1-butanethiol / diethyl ether / 1 h / 20 °C 9.1: 2,4,6-trichlorobenzoyl chloride; triethylamine / tetrahydrofuran / 1 h / 0 °C 9.2: 0.14 g / DMAP / toluene; tetrahydrofuran / 4 h / 20 °C 10.1: 92 percent / zinc; ammonium chloride / methanol / 0.33 h / Heating 11.1: 95 percent / hydrogen fluoride-pyridine / tetrahydrofuran / 16 h / 20 °C 12.1: 30 percent / m-CPBA / CHCl3 / 5 h / -10 - 0 °C View Scheme

1.1: 88 percent / Bu2BOTf; DIPEA / CH2Cl2 / 1 h / -78 °C 2.1: 95 percent / 2,6-lutidine / CH2Cl2 / 1 h / 0 °C 3.1: 76 percent / lithium hydroxide; hydrogen peroxide / tetrahydrofuran; H2O / 4 h / 20 °C 4.1: diisopropylamine; n-butyllithium / tetrahydrofuran; hexane / 1.25 h / -78 - -40 °C 4.2: 59 percent / ZnCl2 / tetrahydrofuran; hexane; diethyl ether / 0.25 h / -78 °C 5.1: pyridine / CH2Cl2 / 1 h / 0 °C 6.1: CH2Cl2 / 5 h / 20 °C 7.1: 0.67 g / acetic acid / tetrahydrofuran; H2O / 3 h / 0 °C 8.1: 72 percent / magnesium bromide; nitromethane; 1-butanethiol / diethyl ether / 1 h / 20 °C 9.1: 2,4,6-trichlorobenzoyl chloride; triethylamine / tetrahydrofuran / 1 h / 0 °C 9.2: 0.14 g / DMAP / toluene; tetrahydrofuran / 4 h / 20 °C 10.1: 92 percent / zinc; ammonium chloride / methanol / 0.33 h / Heating 11.1: 95 percent / hydrogen fluoride-pyridine / tetrahydrofuran / 16 h / 20 °C View Scheme

anhydrous triisopropyl orthoformate; toluene-4-sulfonic acid

1: 74 percent / diethyl ether / 0.5 h / -100 °C 2: 98 percent / 2,6-lutidine / CH2Cl2 / 0.75 h / -78 °C 3: 1) O3, 2) PPh3 / 1) CH2Cl2, -78 deg C, 30 min, 2) Ch2Cl2, -78 deg C -> room temperature; room temperature, 1 h 4: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran / 1) -78 deg C, 5 min, 2) 0 deg C, 15 min 5: 1.26 g / Et3N, 4-DMAP / CH2Cl2 / 1) 0 deg C, 2 h, 2) 25 deg C, 10 h 6: 1) LDA / 1) THF, -78 deg C, 15 min; -78 deg C -> -40 deg C, 1 h, 2) THF, -78 deg C, 15 min 7: 96 percent / 2,6-lutidine / CH2Cl2 / 2 h / 0 °C View Scheme