in diethyl ether T=0°C;

1: oxalyl chloride, DMF / benzene / Ambient temperature 2: benzene; diethyl ether / -10 - -5 °C 3: Rh(OAc)2 / 1 h / Ambient temperature 4: CeCl3*5H2O, NaBH4 / propan-2-ol; H2O 5: pyridine / 0 °C 6: imidazole / dimethylformamide / Ambient temperature 7: 98 percent / H2, pyridine / Lindlar catalyst / hexane / 10 h / 760 Torr 8: 46 percent / 80percent AcOH / 48 h / Ambient temperature 9: 96 percent / CBr4, bis(1,2-diphenylphosphino)ethane (DIPHOS) / CH2Cl2 / 0.5 h / Ambient temperature 10: 1.) CuI, n-BuLi, 2.) HMPA / 1.) THF, hexane, -78 deg C, 15 min, 2.) THF, hexane, a.) from -78 to 0 deg C, 1 h, b) RT, 1 h 11: 61 percent / H2, pyridine / Lindlar catalyst / hexane / 10 h / 760 Torr 12: tetra-n-butylammonium fluoride / tetrahydrofuran / Ambient temperature 13: LiOH / 1,2-dimethoxy-ethane; H2O / Ambient temperature View Scheme

silver nitrate in acetone 16 h;