1: CSA / toluene 2: imidazole, DMAP / dimethylformamide 3: LiAlH4 / tetrahydrofuran / 0 °C 4: 1.) t-BuLi, 2.) O2 / 1.) THF, -78 deg C 5: PCC/Al2O3 6: i-Pr2NEt, DMAP / CH2Cl2 7: 1.) NaN(TMS)2 / 1.) THF, HMPA 8: pyridine*(HF)x / tetrahydrofuran 9: 83 percent / n-Bu4NF 10: 49 percent / 3 N HCl / tetrahydrofuran View Scheme