1: 1.) t-BuLi; / 1.) THF, -78 deg C; 2.) THF/HMPA, -78 deg C; 2: 77 percent / t-BuLi / tetrahydrofuran / -78 deg C then room temp. 4: H2 / 10percent Pd/C / ethanol 5: BH3 / tetrahydrofuran; methanol / Heating 6: 91 percent / 1N HCl / tetrahydrofuran / Ambient temperature 7: 75 percent / Et3N, trifluoracetic acid / dimethylsulfoxide; CH2Cl2 / -78 °C 8: p-TsOH / dioxane / Heating 9: 97 percent / NaBH4 / methanol / -78 deg C then room temp. View Scheme

Multi-step reaction with 2 steps 2: 81 percent / t-BuLi / tetrahydrofuran / 7 h / -78 - 20 °C