4-(N,N-dimethlyamino)pyridine; triethylamine; p-toluenesulfonyl chloride in dichloromethane Ambient temperature;

1: 2.) n-BuLi / 1.) Swern oxid., 2.) THF, -78 deg C 2: 90 percent / Swern oxid. 3: 94 percent / LHMDS / tetrahydrofuran / -78 °C 4: 95 percent / TBAF-HF 6: 78 percent / H2 / Lindlar catalyst 7: O3, pyridine / CH2Cl2 8: NaBH4 / methanol 9: DBU / CH2Cl2 View Scheme

1: 90 percent / Swern oxid. 2: 94 percent / LHMDS / tetrahydrofuran / -78 °C 3: 95 percent / TBAF-HF 5: 78 percent / H2 / Lindlar catalyst 6: O3, pyridine / CH2Cl2 7: NaBH4 / methanol 8: DBU / CH2Cl2 View Scheme

1: 75 percent / imidazole, DMAP / dimethylformamide 2: In / tetrahydrofuran; H2O / Ambient temperature 3: NaH / tetrahydrofuran / Ambient temperature 4: O3, NaOH / CH2Cl2 5: TBAF / tetrahydrofuran / Ambient temperature 6: 72 percent / TsCl, Et3N, DMAP / CH2Cl2 / Ambient temperature View Scheme

1: NaH / tetrahydrofuran / Ambient temperature 2: O3, NaOH / CH2Cl2 3: TBAF / tetrahydrofuran / Ambient temperature 4: 72 percent / TsCl, Et3N, DMAP / CH2Cl2 / Ambient temperature View Scheme

1: NaH / tetrahydrofuran / Ambient temperature 2: O3, NaOH / CH2Cl2 3: TBAF / tetrahydrofuran / Ambient temperature 4: 72 percent / TsCl, Et3N, DMAP / CH2Cl2 / Ambient temperature View Scheme

1: O3, pyridine / CH2Cl2 2: NaBH4 / methanol 3: DBU / CH2Cl2 View Scheme

1: N-bromosuccinmide; water / 1,4-dioxane 2: potassium carbonate / methanol / 6 h / 25 °C / Inert atmosphere 3: triethylsilane; triethylamine / dichloromethane / 0 - 25 °C View Scheme