tetrabutyl ammonium fluoride in tetrahydrofuran T=20°C; 0.5 h;

1.1: hydroxylamine hydrochloride; pyridine / ethanol / 1.17 h / 20 °C / Reflux 1.2: 20 °C 2.1: N-chloro-succinimide / N,N-dimethyl-formamide / 0 - 20 °C 3.1: acetonitrile / 2 h / 0 °C 4.1: trifluoroacetic acid / 0.5 h / 20 °C 5.1: N-ethyl-N,N-diisopropylamine; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / dichloromethane / 3 h / 20 °C 6.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.5 h / 20 °C View Scheme

1.1: triethylamine / dichloromethane / 2 h / 20 °C 2.1: hydroxylamine hydrochloride; pyridine / ethanol / 1.17 h / 20 °C / Reflux 2.2: 20 °C 3.1: N-chloro-succinimide / N,N-dimethyl-formamide / 0 - 20 °C 4.1: acetonitrile / 2 h / 0 °C 5.1: trifluoroacetic acid / 0.5 h / 20 °C 6.1: N-ethyl-N,N-diisopropylamine; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / dichloromethane / 3 h / 20 °C 7.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.5 h / 20 °C View Scheme

1: N,N-dimethyl-formamide / 20 - 100 °C 2: N-ethyl-N,N-diisopropylamine; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / dichloromethane / 3 h / 20 °C 3: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.5 h / 20 °C View Scheme

1: N-ethyl-N,N-diisopropylamine; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / dichloromethane / 3 h / 20 °C 2: tetrabutyl ammonium fluoride / tetrahydrofuran / 0.5 h / 20 °C View Scheme