1: 1) Bu4NOAc, 2) DMAP, Py / 1) CH3CN, 40 deg C, 50 min, 2) 3 h, r.t. 2: 93 percent / NaBH4 / ethanol 3: 93 percent / K2CO3 / methanol / 1 h / 0 °C 4: 1) methyl triflate, 2) N-methylimidazole / 1) THF, 0 deg C, 40 min, 2) THF 5: 89 percent / H2, NaOAc / 10percent Pd/C / methanol 6: 95 percent / CF3COOH / H2O; dioxane View Scheme