1: 58 percent / Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 30 h 2: 78 percent / NaOCH3 / methanol / 5 h / 0 - 5 °C 3: Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 20 h / Ambient temperature 4: DMAP / CH2Cl2 / 4 h / Ambient temperature 5: NaOCH3 / methanol / 0.67 h / 0 - 5 °C 6: 1.) n-BuLi / 1.) THF, hexane, 0-5 deg C; 2.) room temp., 13 h 7: 6 percent / n-Bu4NIO4, Na2HPO4 / CDCl3 / 1.75 h / Ambient temperature View Scheme

Multi-step reaction with 2 steps 1: 58 percent / Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 30 h2: 78 percent / NaOCH3 / methanol / 5 h / 0 - 5 °C  

Multi-step reaction with 3 steps 1: 58 percent / Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 30 h2: 78 percent / NaOCH3 / methanol / 5 h / 0 - 5 °C3: Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 20 h / Ambient temperature  

Multi-step reaction with 6 steps 1: 58 percent / Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 30 h2: 78 percent / NaOCH3 / methanol / 5 h / 0 - 5 °C3: Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 20 h / Ambient temperature4: DMAP / CH2Cl2 / 4 h / Ambient temperature5: NaOCH3 / methanol / 0.67 h / 0 - 5 °C6: 1.) n-BuLi / 1.) THF, hexane, 0-5 deg C; 2.) room temp., 13 h  

Multi-step reaction with 4 steps 1: 58 percent / Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 30 h2: 78 percent / NaOCH3 / methanol / 5 h / 0 - 5 °C3: Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 20 h / Ambient temperature4: DMAP / CH2Cl2 / 4 h / Ambient temperature  

Multi-step reaction with 5 steps 1: 58 percent / Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 30 h2: 78 percent / NaOCH3 / methanol / 5 h / 0 - 5 °C3: Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 20 h / Ambient temperature4: DMAP / CH2Cl2 / 4 h / Ambient temperature5: NaOCH3 / methanol / 0.67 h / 0 - 5 °C  

Multi-step reaction with 7 steps 1: 58 percent / Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 30 h2: 78 percent / NaOCH3 / methanol / 5 h / 0 - 5 °C3: Ph3P, diisopropyl azodicarboxylate / tetrahydrofuran / 20 h / Ambient temperature4: DMAP / CH2Cl2 / 4 h / Ambient temperature5: NaOCH3 / methanol / 0.67 h / 0 - 5 °C6: 1.) n-BuLi / 1.) THF, hexane, 0-5 deg C; 2.) room temp., 13 h7: 75 percent / n-Bu4NIO4, Na2HPO4 / CDCl3 / 1.75 h / Ambient temperature