1: 1) N-chlorosuccinimide, Me2S, 2) NEt3 / 1) toluene, -25 deg C, 5.5 h 2) 20 min 2: HBr, H2O / diethyl ether / 0.5 h / 0 °C 3: NaHCO3, Na2CO3 / H2O / 2.5 h / Ambient temperature 4: 80 percent / pyridine / 20 h / 0 °C 5: pyridine / CH2Cl2 / 0.33 h / -15 °C 6: 1) Bu4NOAc, 2) DMAP, Py / 1) CH3CN, 40 deg C, 50 min, 2) 3 h, r.t. 7: 93 percent / NaBH4 / ethanol 8: 93 percent / K2CO3 / methanol / 1 h / 0 °C 9: 1) methyl triflate, 2) N-methylimidazole / 1) THF, 0 deg C, 40 min, 2) THF 10: 89 percent / H2, NaOAc / 10percent Pd/C / methanol 11: 95 percent / CF3COOH / H2O; dioxane View Scheme