trifluoroacetic acid 6 h; Heating;

diethyl ether; phosphorus pentachloride

1: OsO4, (DHQ)PHAL, K3Fe(CN)6, CH3SO2NH2, K2CO3 / H2O; 2-methyl-propan-2-ol / 24 h / 0 °C 2: 1.) trimethyl orthoacetate, p-TsOH / 1.) CH2Cl2, CH3CN, RT, 1 h, 2.) CH3CN, -15 deg C, 3 h 3: 94 percent / TBAF / tetrahydrofuran / 3 h / Ambient temperature 4: 80 percent / (NH4)2Ce(NO3)6 / H2O; acetonitrile / 1 h / 0 °C 5: 82 percent / methanolic NaHCO3, Na2CO3 / Ambient temperature View Scheme

aluminium trichloride in chlorobenzene T=120°C; 2 h;

1: OsO4, (DHQ)PHAL, K3Fe(CN)6, CH3SO2NH2, K2CO3 / H2O; 2-methyl-propan-2-ol / 24 h / 0 °C 2: 1.) trimethyl orthoacetate, p-TsOH / 1.) CH2Cl2, CH3CN, RT, 1 h, 2.) CH3CN, -15 deg C, 3 h 3: 94 percent / TBAF / tetrahydrofuran / 3 h / Ambient temperature 4: 80 percent / (NH4)2Ce(NO3)6 / H2O; acetonitrile / 1 h / 0 °C View Scheme

1: 82 percent / aluminium chloride / chlorobenzene / 2 h / 100 - 110 °C 2: 61.7 percent / K2CO3, KI / dimethylsulfoxide / 24 h / Ambient temperature 3: 95 percent / KOH / methanol / 1 h / Heating 4: 32 percent / isobutyl chloroformiate, triethylamine / dimethylformamide / 0.25 h / 0 °C View Scheme

1: 82 percent / aluminium chloride / chlorobenzene / 2 h / 100 - 110 °C 2: 47 percent / K2CO3, KI / dimethylsulfoxide / 5 h / 70 °C 3: 93 percent / KOH / methanol / 1 h / Heating View Scheme

1: 82 percent / aluminium chloride / chlorobenzene / 2 h / 100 - 110 °C 2: 61.7 percent / K2CO3, KI / dimethylsulfoxide / 24 h / Ambient temperature 3: 95 percent / KOH / methanol / 1 h / Heating View Scheme

1: 82 percent / aluminium chloride / chlorobenzene / 2 h / 100 - 110 °C 2: 59.5 percent / K2CO3, KI / dimethylsulfoxide / 24 h / Ambient temperature 3: 72 percent / KOH / methanol / 1 h / Heating View Scheme