1: LiOH*H2O, aq. H2O2 / tetrahydrofuran / 11 h / Ambient temperature 2: diethylphosphoryl cyanide, Et3N / dimethylformamide / 2 h / Ambient temperature 3: 99 percent / tetrahydrofuran; diethyl ether / 0.33 h / -78 °C 4: 1.) LDA / 1.) THF, -78 deg C, 1 h, 2.) THF, -78 deg C, 1 h 5: 1.) 4-dimethylaminopyridine, 2.) DBU / 1.) CH2Cl2, RT, 12 h, 2.) CH2Cl2, from 0 to 20 deg C, 2 h 6: NaBH4, Te, AcOH / ethanol / 4 h / Ambient temperature 7: L-Selectride / tetrahydrofuran / -80 - -30 °C 8: 89 percent / i-Pr2NEt / CH2Cl2 / 0.67 h / -40 °C 9: 81 percent / NBS, AgNO3, 2,4,6-collidine / acetonitrile / 0.17 h / 0 °C 10: 100 percent / L-Selectride / tetrahydrofuran / -40 - -30 °C 11: 89 percent / i-Pr2NEt / CH2Cl2 / 20 h / Ambient temperature 12: 94 percent / H2 / Raney Ni (W2) / ethanol / 72 h / 760 Torr 13: 88 percent / i-Pr2NEt / CH2Cl2 / -40 - -20 °C 14: HF*pyridine / tetrahydrofuran / 60 h / Ambient temperature 15: i-Pr2NEt / CH2Cl2 / 0.5 h / -40 - -20 °C 16: DIBAL-H / CH2Cl2; hexane / 0.5 h / -78 °C 17: DMAP / toluene / 12 h / 50 °C 18: 76 percent / DDQ / CH2Cl2; H2O / 1.5 h / Ambient temperature 19: 87 percent / TPAP, NMO, MS4A / acetonitrile / 1 h / Ambient temperature 20: 1.) NBS, 2.) CrO3, H2SO4 / 1.) THF, phosphate buffer pH 7, 0 deg C, 15 min, 2.) acetone, 0 deg C, 15 min 21: MS 4A, PPC / CH2Cl2 / 12 h / Ambient temperature 22: HF*pyridine / tetrahydrofuran / Ambient temperature View Scheme