1: 63 percent / N,N-dicyclohexylcarbodimide / dioxane / 4 h / Ambient temperature 2: 24 percent / 1N aq. NaOH / methanol; acetonitrile / 0.5 h / Ambient temperature 3: 6.1 mg / H2 / 5percent Pd/C / methanol / 3 h / Ambient temperature 4: 39 percent / N,N-dicyclohexylcarbodimide / dioxane / 15 h 5: 60 percent / AlCl3 / CH2Cl2 / 2 h / Ambient temperature View Scheme

1.1: 97 percent / PyBrOP; diisopropylethylamine / dimethylformamide / 0 - 20 °C 2.1: trifluoroacetic acid / 0.33 h / 20 °C 2.2: 63 percent / diisopropylethylamine; 1-hydroxybenzotriazole; 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride / CH2Cl2 / 24 h / 20 °C 3.1: 82 percent / LiOH*H2O / tetrahydrofuran; methanol; H2O / 1 h / 20 °C 4.1: HCl / ethyl acetate / 1 h 5.1: 2.5 mg / NaHCO3; diphenylphosphoryl azide / dimethylformamide / 72 h / 5 °C View Scheme

Multi-step reaction with 5 steps 1: DCC / dioxane; CH2Cl2 2: 0.2 N aq. NaOH / methanol; acetonitrile3: H2 / 5percent Pd/C4: 39 percent / DCC / dioxane5: 100 percent / AlCl3, EtSH  

With  dicyclohexyl-carbodiimide in  1,4-dioxane 4 h;  Ambient temperature;   

Multi-step reaction with 4 steps 1.1: 97 percent / PyBrOP; diisopropylethylamine / dimethylformamide / 0 - 20 °C2.1: trifluoroacetic acid / 0.33 h / 20 °C2.2: 63 percent / diisopropylethylamine; 1-hydroxybenzotriazole; 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride / CH2Cl2 / 24 h / 20 °C3.1: 82 percent / LiOH*H2O / tetrahydrofuran; methanol; H2O / 1 h / 20 °C4.1: HCl / ethyl acetate / 1 h  

With  hydrogen; potassium acetate; palladium on activated charcoal in  methanol  Ambient temperature;