1: With ozone in dichloromethane T=-78°C; 2: With pyridine in tetrachloromethane; dichloromethane 1.5 h; Heating;

1: 85 percent / p-toluenesulfonic acid 2: 92 percent / tetrahydrofuran / 1 h / -78 °C 3: 60 percent Turnov. / diethyl ether / 84 h / -24 °C 4: hydrogen / 10percent Pd(C) / aq. ethanol 5: 63 percent / DIBAL-H / 1.) -40 deg C, 1.0 h, 2.) 0 deg C, 0.5 h 6: 71 percent / Et3N, 4-N,N-dimethylaminopyridine View Scheme

1: 92 percent / tetrahydrofuran / 1 h / -78 °C 2: 60 percent Turnov. / diethyl ether / 84 h / -24 °C 3: hydrogen / 10percent Pd(C) / aq. ethanol 4: 63 percent / DIBAL-H / 1.) -40 deg C, 1.0 h, 2.) 0 deg C, 0.5 h 5: 71 percent / Et3N, 4-N,N-dimethylaminopyridine View Scheme

1: 65 percent / LDA / tetrahydrofuran 2: 85 percent / p-toluenesulfonic acid 3: 92 percent / tetrahydrofuran / 1 h / -78 °C 4: 60 percent Turnov. / diethyl ether / 84 h / -24 °C 5: hydrogen / 10percent Pd(C) / aq. ethanol 6: 63 percent / DIBAL-H / 1.) -40 deg C, 1.0 h, 2.) 0 deg C, 0.5 h 7: 71 percent / Et3N, 4-N,N-dimethylaminopyridine View Scheme

1: 60 percent Turnov. / diethyl ether / 84 h / -24 °C 2: hydrogen / 10percent Pd(C) / aq. ethanol 3: 63 percent / DIBAL-H / 1.) -40 deg C, 1.0 h, 2.) 0 deg C, 0.5 h 4: 71 percent / Et3N, 4-N,N-dimethylaminopyridine View Scheme

1: hydrogen / 10percent Pd(C) / aq. ethanol 2: 63 percent / DIBAL-H / 1.) -40 deg C, 1.0 h, 2.) 0 deg C, 0.5 h 3: 71 percent / Et3N, 4-N,N-dimethylaminopyridine View Scheme

4-(N,N-dimethlyamino)pyridine; triethylamine 16 h; Ambient temperature;

1.1: 54 percent / imidazole; iodine; triphenylphosphine / 2,6-lutidine / benzene; 1,2-dichloro-ethane; H2O / 0.25 h / 80 °C 2.1: 51 percent / p-TsOH / CH2Cl2 / 2.3 h / 20 °C 3.1: 75 percent / p-TsOH; N-(phenylseleno)phthalimide / CH2Cl2 / 6.5 h / 20 °C 4.1: 60 percent / 4-(dimethylamino)pyridine / pyridine / 24 h / 40 °C 5.1: ozone / CH2Cl2 / -78 °C 5.2: 62 percent / pyridine / CH2Cl2; CCl4 / 1.5 h / Heating View Scheme

1.1: 173 mg / triethylamine; 4-(dimethylamino)pyridine / CH2Cl2 / 2.75 h / 20 °C 2.1: 82 percent / KOH / H2O; methanol / 1 h / 20 °C 3.1: oxalyl chloride / dimethylformamide; benzene / 1 h / 20 °C 4.1: CH2Cl2 / 2 h / 20 °C 5.1: 115 mg / (PHS)3Sb; air / diethyl ether / 1.5 h / 20 °C 6.1: 79 percent / pyridinium chlorochromate; sodium acetate / CH2Cl2 / 2 h / 20 °C 7.1: 96 percent / diethyl ether / 0.75 h / -78 °C 8.1: 100 percent / tetrabutylammonium fluoride / tetrahydrofuran / 2.5 h / 20 °C 9.1: 54 percent / imidazole; iodine; triphenylphosphine / 2,6-lutidine / benzene; 1,2-dichloro-ethane; H2O / 0.25 h / 80 °C 10.1: 51 percent / p-TsOH / CH2Cl2 / 2.3 h / 20 °C 11.1: 75 percent / p-TsOH; N-(phenylseleno)phthalimide / CH2Cl2 / 6.5 h / 20 °C 12.1: 60 percent / 4-(dimethylamino)pyridine / pyridine / 24 h / 40 °C 13.1: ozone / CH2Cl2 / -78 °C 13.2: 62 percent / pyridine / CH2Cl2; CCl4 / 1.5 h / Heating View Scheme

1.1: KOH / H2O; methanol / 23 h / 40 °C 2.1: 173 mg / triethylamine; 4-(dimethylamino)pyridine / CH2Cl2 / 2.75 h / 20 °C 3.1: 82 percent / KOH / H2O; methanol / 1 h / 20 °C 4.1: oxalyl chloride / dimethylformamide; benzene / 1 h / 20 °C 5.1: CH2Cl2 / 2 h / 20 °C 6.1: 115 mg / (PHS)3Sb; air / diethyl ether / 1.5 h / 20 °C 7.1: 79 percent / pyridinium chlorochromate; sodium acetate / CH2Cl2 / 2 h / 20 °C 8.1: 96 percent / diethyl ether / 0.75 h / -78 °C 9.1: 100 percent / tetrabutylammonium fluoride / tetrahydrofuran / 2.5 h / 20 °C 10.1: 54 percent / imidazole; iodine; triphenylphosphine / 2,6-lutidine / benzene; 1,2-dichloro-ethane; H2O / 0.25 h / 80 °C 11.1: 51 percent / p-TsOH / CH2Cl2 / 2.3 h / 20 °C 12.1: 75 percent / p-TsOH; N-(phenylseleno)phthalimide / CH2Cl2 / 6.5 h / 20 °C 13.1: 60 percent / 4-(dimethylamino)pyridine / pyridine / 24 h / 40 °C 14.1: ozone / CH2Cl2 / -78 °C 14.2: 62 percent / pyridine / CH2Cl2; CCl4 / 1.5 h / Heating View Scheme