trifluoroacetic acid T=21°C; 2 h;

1: 80 percent / glacial acetic acid / H2O / 16 h / 60 °C 2: 50 percent / hexamethylenetetramine, 66percent aq. propionic acid / 1.) 21 deg C, 1 h, 2.) 100 deg C, 2 h 3: 1.) NaH / 1.) HMPA, 21 deg C, 2.) HMPA, 3 h 4: 60 percent / NaBH4 / aq. ethanol / 4 h / 21 °C 5: 45 percent / Ph3P, CCl4 / dimethylformamide / 108 h / 21 °C 6: 96 percent / NaI / acetone / 24 h / 21 °C 7: 1.) potassium bis(trimethylsilyl)amide / 1.) toluene, THF, HMPA, -100 to -78 deg C, 30 min, 2.) THF, -100 deg C, 3 h 8: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 9: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme

1: 1.) NaH / 1.) HMPA, 21 deg C, 2.) HMPA, 3 h 2: 60 percent / NaBH4 / aq. ethanol / 4 h / 21 °C 3: 45 percent / Ph3P, CCl4 / dimethylformamide / 108 h / 21 °C 4: 96 percent / NaI / acetone / 24 h / 21 °C 5: 1.) potassium bis(trimethylsilyl)amide / 1.) toluene, THF, HMPA, -100 to -78 deg C, 30 min, 2.) THF, -100 deg C, 3 h 6: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 7: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme

1: 50 percent / hexamethylenetetramine, 66percent aq. propionic acid / 1.) 21 deg C, 1 h, 2.) 100 deg C, 2 h 2: 1.) NaH / 1.) HMPA, 21 deg C, 2.) HMPA, 3 h 3: 60 percent / NaBH4 / aq. ethanol / 4 h / 21 °C 4: 45 percent / Ph3P, CCl4 / dimethylformamide / 108 h / 21 °C 5: 96 percent / NaI / acetone / 24 h / 21 °C 6: 1.) potassium bis(trimethylsilyl)amide / 1.) toluene, THF, HMPA, -100 to -78 deg C, 30 min, 2.) THF, -100 deg C, 3 h 7: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 8: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme

1: 60 percent / NaBH4 / aq. ethanol / 4 h / 21 °C 2: 45 percent / Ph3P, CCl4 / dimethylformamide / 108 h / 21 °C 3: 96 percent / NaI / acetone / 24 h / 21 °C 4: 1.) potassium bis(trimethylsilyl)amide / 1.) toluene, THF, HMPA, -100 to -78 deg C, 30 min, 2.) THF, -100 deg C, 3 h 5: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 6: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme

1: 45 percent / Ph3P, CCl4 / dimethylformamide / 108 h / 21 °C 2: 96 percent / NaI / acetone / 24 h / 21 °C 3: 1.) potassium bis(trimethylsilyl)amide / 1.) toluene, THF, HMPA, -100 to -78 deg C, 30 min, 2.) THF, -100 deg C, 3 h 4: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 5: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme

1: 1.) lithium diisopropylamide / 1.) THF, -100 to -78 deg C, 30 min, 2.) THF, -100 deg C, 2 h 2: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 3: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme

1: 96 percent / NaI / acetone / 24 h / 21 °C 2: 1.) potassium bis(trimethylsilyl)amide / 1.) toluene, THF, HMPA, -100 to -78 deg C, 30 min, 2.) THF, -100 deg C, 3 h 3: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 4: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme

1: 1.) potassium bis(trimethylsilyl)amide / 1.) toluene, THF, HMPA, -100 to -78 deg C, 30 min, 2.) THF, -100 deg C, 3 h 2: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 3: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme

1: 69 percent / hydroxylamine hydrochloride, Na acetate / aq. ethanol / 72 h / 21 °C 2: 69 percent / trifluoroacetic acid / 2 h / 21 °C View Scheme