1: HCl / methanol / 0.5 h / Ambient temperature 2: LiOH / tetrahydrofuran; methanol; H2O / 24 h / Ambient temperature 3: N-ethyldiisopropylamine, bis(2-oxo-3-oxazolidinyl)phosphic chloride / toluene / 15 h / 85 °C 4: 100 percent / TBAF / tetrahydrofuran / 44 h / Ambient temperature 5: 91 percent / trifluoroacetic acid / CH2Cl2 / 17 h / Ambient temperature 6: 100 percent / AgO, 1 M aq. HNO3 / dioxane / 2.5 h / Ambient temperature View Scheme