1: 87 percent / pyridine / 3 h / Heating 2: 80 percent / NH3 / diethyl ether / 12 h / Ambient temperature 3: 92 percent / Ag2O / diethyl ether / 1 h 4: 86 percent / TFA / CH2Cl2 / 2 h / Ambient temperature 5: 72 percent / 0.2N KOH, KMnO4 / dioxane / 2 h / Ambient temperature 6: 73 percent / N,N'-dicyclohexylcarbodiimide / dioxane; ethyl acetate / 6 h / Ambient temperature View Scheme

1: 87 percent / pyridine / 3 h / Heating 2: 80 percent / NH3 / diethyl ether / 12 h / Ambient temperature 3: 92 percent / Ag2O / diethyl ether / 1 h 4: 86 percent / TFA / CH2Cl2 / 2 h / Ambient temperature View Scheme

1: 87 percent / pyridine / 3 h / Heating 2: 80 percent / NH3 / diethyl ether / 12 h / Ambient temperature 3: 92 percent / Ag2O / diethyl ether / 1 h 4: 86 percent / TFA / CH2Cl2 / 2 h / Ambient temperature 5: 72 percent / 0.2N KOH, KMnO4 / dioxane / 2 h / Ambient temperature View Scheme