1: 91 percent / Ag2O / diethyl ether / 1 h 2: 92 percent / conc. HCl / methanol 3: 72 percent / 0.2N KOH, KMnO4 / dioxane / 2 h / Ambient temperature 4: 73 percent / N,N'-dicyclohexylcarbodiimide / dioxane; ethyl acetate / 6 h / Ambient temperature View Scheme

1: 91 percent / Ag2O / diethyl ether / 1 h 2: 92 percent / conc. HCl / methanol View Scheme

1: 91 percent / Ag2O / diethyl ether / 1 h 2: 92 percent / conc. HCl / methanol 3: 72 percent / 0.2N KOH, KMnO4 / dioxane / 2 h / Ambient temperature View Scheme

ammonium hydroxide in tetrahydrofuran T=-78 - 20°C; 48 h; Sealed tube;

1: 93 percent / NH3OHCl, NaOH / ethanol / 16 h / Heating 2: 70 percent / pyridine / 3 h / Heating 3: 86 percent / liq. NH3 / diethyl ether / 12 h / Ambient temperature View Scheme

1: 1) n-BuLi / 1) hexane, ether, -30 to 0 deg C in 2 h, 2) ether, -50 deg C, 3 h 2: 93 percent / NH3OHCl, NaOH / ethanol / 16 h / Heating 3: 70 percent / pyridine / 3 h / Heating 4: 86 percent / liq. NH3 / diethyl ether / 12 h / Ambient temperature View Scheme

1: 97 percent / imidazole 2: 1) n-BuLi / 1) hexane, ether, -30 to 0 deg C in 2 h, 2) ether, -50 deg C, 3 h 3: 93 percent / NH3OHCl, NaOH / ethanol / 16 h / Heating 4: 70 percent / pyridine / 3 h / Heating 5: 86 percent / liq. NH3 / diethyl ether / 12 h / Ambient temperature View Scheme

1: 97 percent / imidazole 2: 1) n-BuLi / 1) hexane, ether, -30 to 0 deg C in 2 h, 2) ether, -50 deg C, 3 h 3: 93 percent / NH3OHCl, NaOH / ethanol / 16 h / Heating 4: 70 percent / pyridine / 3 h / Heating 5: 86 percent / liq. NH3 / diethyl ether / 12 h / Ambient temperature View Scheme

1: 70 percent / pyridine / 3 h / Heating 2: 86 percent / liq. NH3 / diethyl ether / 12 h / Ambient temperature View Scheme

1.1: 1H-imidazole / N,N-dimethyl-formamide / 2 h / 20 °C 2.1: n-butyllithium / tetrahydrofuran; hexane / 0.75 h / -78 °C 2.2: 1.25 h / -78 °C 3.1: pyridine; hydroxylamine hydrochloride / ethanol / 60 °C 4.1: triethylamine; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 20 °C 5.1: ammonium hydroxide / tetrahydrofuran / 48 h / -78 - 20 °C / |Sealed tube View Scheme