1: aq. citric acid 2: 73 percent / K2CO3 / dimethylformamide / 25 °C 3: 100 percent / Et3N; DMAP / tetrahydrofuran / 0 °C 4: AcCl / methanol; toluene / 0 °C 5: NaBH3CN / tetrahydrofuran; H2O / 5 °C 6: H2O / 25 °C 7: 77 percent / NaHCO3; P(OEt)3; n-Bu4NCl / Pd(OAc)2 / dimethylformamide / 100 °C 8: H2 / Pd(OH)2/C / ethyl acetate / 25 °C 9: aq. HBr / Heating View Scheme