1: 50 percent / LiTi(Oi-Pr)4(SPh) / tetrahydrofuran; hexane / 72 h / Ambient temperature 2: 94 percent / DIBAL-H / hexane; CH2Cl2 / 4 h / -78 °C 3: 93 percent / chiral dioxaborolane catalyst / CH2Cl2 / 40 h / Ambient temperature 4: 1.) NaH / 1.) THF, RT, 45 min, 2.) THF, RT, 45 min 5: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 6: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 7: 63 percent / LiTi(Oi-Pr)4(SPh) / tetrahydrofuran; hexane / 72 h / Ambient temperature 8: 91 percent / DIBAL-H / hexane; CH2Cl2 / 4 h / -78 °C 9: 90 percent / chiral dioxaborolane catalyst / CH2Cl2; hexane / 168 h / -40 °C 10: 1.) n-Bu3P / 1.) benzene, RT, 10 min, 2.) benzene, RT, 1.5 h 11: W-2 Raney nickel / ethanol / 48 h / -60 °C 12: NH4F / ethanol / 26 h / 65 °C 13: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 14: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 15: 85 percent / potassium trimethylsilanolate / CH2Cl2 / Ambient temperature 16: Et3N / N,N-dimethyl-acetamide / 3 h / Ambient temperature 17: Et3N / 24 h / Ambient temperature View Scheme