1: 90 percent / aq. NaOH / dioxane / 12 h / Ambient temperature 2: 73 percent / dicyclohexylcarbodiimide / 1.) 2 h, ice-bath; 2.) room temp., 12 h 3: 82 percent / triethylamine / dimethylformamide / 24 h View Scheme

sodium hydroxide in 1,4-dioxane 12 h; Ambient temperature;