1: 23 percent / (C6H11)2NMgBr / tetrahydrofuran / -55 °C 2: 95 percent / DDQ / CH2Cl2; H2O / 0.17 h / Ambient temperature 3: 70 percent / TFA, molecular sieves / CH2Cl2 View Scheme

Multi-step reaction with 8 steps 2: 99 percent / DMSO, (COCl)2, Et3N / CH2Cl2 3: Ph3P / CH2Cl2 / -78 °C4: LDA / tetrahydrofuran / -30 °C5: n-BuLi / 1.) THF, -78 deg C, 2.) oxidation6: 1.) camphorsulfonic acid, 2.) n-Bu4NF / 1.) room temperature, 2.) dioxane-THF, 65 deg C7: 88 percent / H2 / Lindlar / methanol8: 1.) DMSO, (COCl)2, Et3N, 2.) CSA / 1.) CH2Cl2, 2.) CH2Cl2, room temperature  

Multi-step reaction with 7 steps 1: 99 percent / DMSO, (COCl)2, Et3N / CH2Cl2 2: Ph3P / CH2Cl2 / -78 °C3: LDA / tetrahydrofuran / -30 °C4: n-BuLi / 1.) THF, -78 deg C, 2.) oxidation5: 1.) camphorsulfonic acid, 2.) n-Bu4NF / 1.) room temperature, 2.) dioxane-THF, 65 deg C6: 88 percent / H2 / Lindlar / methanol7: 1.) DMSO, (COCl)2, Et3N, 2.) CSA / 1.) CH2Cl2, 2.) CH2Cl2, room temperature  

Multi-step reaction with 4 steps 1: n-BuLi / 1.) THF, -78 deg C, 2.) oxidation2: 1.) camphorsulfonic acid, 2.) n-Bu4NF / 1.) room temperature, 2.) dioxane-THF, 65 deg C3: 88 percent / H2 / Lindlar / methanol4: 1.) DMSO, (COCl)2, Et3N, 2.) CSA / 1.) CH2Cl2, 2.) CH2Cl2, room temperature  

Multi-step reaction with 9 steps 3: 99 percent / DMSO, (COCl)2, Et3N / CH2Cl2 4: Ph3P / CH2Cl2 / -78 °C5: LDA / tetrahydrofuran / -30 °C6: n-BuLi / 1.) THF, -78 deg C, 2.) oxidation7: 1.) camphorsulfonic acid, 2.) n-Bu4NF / 1.) room temperature, 2.) dioxane-THF, 65 deg C8: 88 percent / H2 / Lindlar / methanol9: 1.) DMSO, (COCl)2, Et3N, 2.) CSA / 1.) CH2Cl2, 2.) CH2Cl2, room temperature