Multi-step reaction with 10 steps 1: 1.) diisopropylamine, BuLi / 1.) THF, hexane, a) -50 deg C, 15 min, b) RT, 1 h, 2.) -78 deg C, 3 h2: H2 / 10percent Pd/C / tetrahydrofuran / 760 Torr / Ambient temperature3: p-TsOH, / CHCl3 / Ambient temperature4: Jones' reagent / acetone / 1 h / 10 °C5: 84 percent / H2 / PtO2 / ethyl acetate / 48 h / 37503 Torr / Ambient temperature6: 73 percent / CF3SO3H / CH2Cl2 / 2 h / 0 - 20 °C7: 1.) 1 N KOH / 1.) dioxane, water, RT, 5 h, 2.) THF, HMPA, 24 h8: 73 percent / p-toluenesulfonic acid / CH2Cl2 / 3 h / -10 - 20 °C9: H2 / 10percent Pd/C / tetrahydrofuran / 4 h / 760 Torr / Ambient temperature10: benzenesulfonylchloride, pyridine / 0 °C  

Multi-step reaction with 5 steps 1: TiCl4 / CH2Cl2 / 0.75 h / -78 °C2: 97 percent / CF3SO3Ag / CH2Cl2 / 2 h / Ambient temperature3: 1.) LDA / 1.) THF, -50 deg C, 40 min; -30 deg C, 40 min, 2.) HMPA, -50 deg C, 1 h; -20 deg C, 2 h; 0 deg C, 1 h4: 1 N KOH / ethanol / 4 h / 50 °C5: benzenesulfonyl chloride, pyridine / 0 °C  

Multi-step reaction with 4 steps 1: TiCl4 / CH2Cl2 / 0.75 h / -78 °C2: 97 percent / CF3SO3Ag / CH2Cl2 / 2 h / Ambient temperature3: 1.) LDA / 1.) THF, -50 deg C, 40 min; -30 deg C, 40 min, 2.) HMPA, -50 deg C, 1 h; -20 deg C, 2 h; 0 deg C, 1 h4: 1 N KOH / ethanol / 4 h / 50 °C