potassium hydroxide in methanol; water T=20°C; 3 h;

1.1: LDA / tetrahydrofuran; hexane / 1 h / -60 °C 1.2: 64 percent / tetrahydrofuran; hexane / 0.5 h / -60 °C 2.1: 100 percent / HBr; AcOH / H2O / 1 h / Heating 3.1: 60 percent / SOCl2 / 18 h / 70 °C 4.1: 80 percent / Cs2CO3 / dimethylformamide / 1.5 h / 110 °C 5.1: 97 percent / KOH / methanol; H2O / 3 h / 20 °C View Scheme

1: 100 percent / HBr; AcOH / H2O / 1 h / Heating 2: 60 percent / SOCl2 / 18 h / 70 °C 3: 80 percent / Cs2CO3 / dimethylformamide / 1.5 h / 110 °C 4: 97 percent / KOH / methanol; H2O / 3 h / 20 °C View Scheme

1: 60 percent / SOCl2 / 18 h / 70 °C 2: 80 percent / Cs2CO3 / dimethylformamide / 1.5 h / 110 °C 3: 97 percent / KOH / methanol; H2O / 3 h / 20 °C View Scheme

1: 80 percent / Cs2CO3 / dimethylformamide / 1.5 h / 110 °C 2: 97 percent / KOH / methanol; H2O / 3 h / 20 °C View Scheme

1: 93 percent / diphenoxyphosphoryl azide; Et3N / dioxane / 4.5 h / 100 °C 2: 94 percent / TFA / CH2Cl2 / 3 h / 20 °C View Scheme

diphenyl phosphoryl azide; triethylamine in 1,4-dioxane T=100°C; 4.5 h;