1: 74 percent / triphenylphosphine; N-bromosuccinimide / tetrahydrofuran / 0 - 20 °C 2: 83 percent / sodium sulfite; H2O / dioxane / 1 h / Heating 3: aq. sodium carbonate / acetonitrile / 16 h / 20 °C 4: CH2Cl2; H2O / 2 h / 20 °C 5: 100.0 mg / triethylamine / H2O; acetonitrile / 0.5 h / 20 °C / pH 8.5 - 9.0 View Scheme