zinc in acetic acid T=47°C; 1 h;

methanol; 10 Pd on charcoal; hydrogen in acetic acid T=23°C;

1: Et3N / toluene / 1 h / 25 °C 2: DMAP / 16 h / 25 °C 3: HBr / CH2Cl2 / 3 h / -10 °C 4: NaHCO3 / methanol / 3 h View Scheme

1: 37 percent / 1,2-dimethoxy-ethane / 2 h / 105 °C 2: 94 percent / Zn / acetic acid / 1 h / 47 °C View Scheme

1: 1) O3, 2) Me2S / 1) CH2Cl2, -78 degC, 2) room temp., 1 h 2: oxalyl chloride, pyridine / benzene / 6 h / Ambient temperature 3: pyridine, 4-(dimethylamino)pyridine / CH2Cl2 / 6 h / Ambient temperature 4: 90.5 percent / ZnCl2, K / tetrahydrofuran / 1) room temp., 1 h, 2) 40-50 degC, 1 h 5: 10 percent / tetrahydrofuran / 1) -78 degC, 2) -20 degC, 30 min View Scheme

1: 78.6 percent / AgNO3, 8percent KOH / ethanol; H2O / 2 h / 0 °C 2: 1) O3, 2) Me2S / 1) CH2Cl2, -78 degC, 2) room temp., 1 h 3: oxalyl chloride, pyridine / benzene / 6 h / Ambient temperature 4: pyridine, 4-(dimethylamino)pyridine / CH2Cl2 / 6 h / Ambient temperature 5: 90.5 percent / ZnCl2, K / tetrahydrofuran / 1) room temp., 1 h, 2) 40-50 degC, 1 h 6: 10 percent / tetrahydrofuran / 1) -78 degC, 2) -20 degC, 30 min View Scheme

1: oxalyl chloride, pyridine / benzene / 6 h / Ambient temperature 2: pyridine, 4-(dimethylamino)pyridine / CH2Cl2 / 6 h / Ambient temperature 3: 90.5 percent / ZnCl2, K / tetrahydrofuran / 1) room temp., 1 h, 2) 40-50 degC, 1 h 4: 10 percent / tetrahydrofuran / 1) -78 degC, 2) -20 degC, 30 min View Scheme

1: 90.5 percent / ZnCl2, K / tetrahydrofuran / 1) room temp., 1 h, 2) 40-50 degC, 1 h 2: 10 percent / tetrahydrofuran / 1) -78 degC, 2) -20 degC, 30 min View Scheme

1: pyridine, 4-(dimethylamino)pyridine / CH2Cl2 / 6 h / Ambient temperature 2: 90.5 percent / ZnCl2, K / tetrahydrofuran / 1) room temp., 1 h, 2) 40-50 degC, 1 h 3: 10 percent / tetrahydrofuran / 1) -78 degC, 2) -20 degC, 30 min View Scheme

sodium hydrogencarbonate in methanol 3 h; Yield given;