sodium hydroxide in tetrahydrofuran; water T=20°C;

hydrogen fluoride in acetonitrile 4 h; Ambient temperature;

1: imidazole / dimethylformamide / 10 h 2: 1.) lithium bis(trimethylsilyl)amide, 2.) hexamethylphosphoric triamide / 1.) THF, from -78 deg C to 0 deg C, 1 h, 2.) from -78 deg C to RT, 2 h 3: 1.) lithium bis(trimethylsilyl)amide, 2.) hexamethylphosphoric triamide / 1.) THF, -78 deg C, 2.) from -78 deg C to RT, 2 h 4: 95 percent / 40percent aq. HF / acetonitrile / 4 h / Ambient temperature View Scheme

1: 1.) lithium bis(trimethylsilyl)amide, 2.) hexamethylphosphoric triamide / 1.) THF, from -78 deg C to 0 deg C, 1 h, 2.) from -78 deg C to RT, 2 h 2: 1.) lithium bis(trimethylsilyl)amide, 2.) hexamethylphosphoric triamide / 1.) THF, -78 deg C, 2.) from -78 deg C to RT, 2 h 3: 95 percent / 40percent aq. HF / acetonitrile / 4 h / Ambient temperature View Scheme

1: 1.) lithium bis(trimethylsilyl)amide, 2.) hexamethylphosphoric triamide / 1.) THF, -78 deg C, 2.) from -78 deg C to RT, 2 h 2: 95 percent / 40percent aq. HF / acetonitrile / 4 h / Ambient temperature View Scheme

1: (COCl)2; DMSO; Et3N / CH2Cl2 / -60 - 20 °C 2: 2-methyl-2-butene; NaH2PO4*2H2O; NaClO2 / 2-methyl-propan-2-ol; H2O / 1 h / 20 °C 3: 88 percent / NaOH / tetrahydrofuran; H2O / 20 °C View Scheme

1: 90 percent / N-bromosuccinimide (NBS) / CH2Cl2 / 0.5 h / -40 °C 2: 82 percent / Bun3SnCl, NaCNBH3, azoisobutyronitrile (AIBN) / 2-methyl-propan-2-ol / 1.5 h / Heating 3: 79 percent / Jones' reagent / acetone / Irradiation View Scheme

1: 80 percent / EtC(Me2)OK / tetrahydrofuran; various solvent(s) / Ambient temperature 2: 90 percent / N-bromosuccinimide (NBS) / CH2Cl2 / 0.5 h / -40 °C 3: 82 percent / Bun3SnCl, NaCNBH3, azoisobutyronitrile (AIBN) / 2-methyl-propan-2-ol / 1.5 h / Heating 4: 79 percent / Jones' reagent / acetone / Irradiation View Scheme