1: 89 percent / p-toluenesulfonic acid / 8 h / Heating 2: CaCO3, Br2, sodium thiosulfate, LiBr, Li2CO3, p-toluenesulfonic acid 3: 84.1 percent / pyridine; ethanol / 22 h / Ambient temperature 4: 85.9 percent / 25percent (i-Bu)2AlH / benzene; hexane / 1.5 h / 0 - 5 °C / 1) 0-5 deg C, 1.5h, 2) 15 min 5: 86.2 percent / triethylamine / CH2Cl2 / 0.5 h / cooling 6: 1) 57percent NaH / 1) 1h, DME; 2) DME, 16h, reflux 7: KOH / methanol; H2O / 18 h / Heating 8: various solvent(s) / Heating 9: 2N HCl / acetone / 5 h / Heating 10: 80.6 percent / p-toluenesulfonic acid / 5 h / Heating View Scheme

1: 89 percent / p-toluenesulfonic acid / 8 h / Heating 2: CaCO3, Br2, sodium thiosulfate, LiBr, Li2CO3, p-toluenesulfonic acid 3: 84.1 percent / pyridine; ethanol / 22 h / Ambient temperature 4: 85.9 percent / 25percent (i-Bu)2AlH / benzene; hexane / 1.5 h / 0 - 5 °C / 1) 0-5 deg C, 1.5h, 2) 15 min 5: 86.2 percent / triethylamine / CH2Cl2 / 0.5 h / cooling 6: 1) 57percent NaH / 1) 1h, DME; 2) DME, 16h, reflux 7: KOH / methanol; H2O / 18 h / Heating 8: various solvent(s) / Heating 9: 2N HCl / acetone / 5 h / Heating 10: 87 percent / p-toluenesulfonic acid / 17 h / Heating View Scheme

1: 89 percent / p-toluenesulfonic acid / 8 h / Heating 2: CaCO3, Br2, sodium thiosulfate, LiBr, Li2CO3, p-toluenesulfonic acid 3: 84.1 percent / pyridine; ethanol / 22 h / Ambient temperature 4: 85.9 percent / 25percent (i-Bu)2AlH / benzene; hexane / 1.5 h / 0 - 5 °C / 1) 0-5 deg C, 1.5h, 2) 15 min 5: 86.2 percent / triethylamine / CH2Cl2 / 0.5 h / cooling 6: 1) 57percent NaH / 1) 1h, DME; 2) DME, 16h, reflux 7: KOH / methanol; H2O / 18 h / Heating 8: various solvent(s) / Heating 9: 2N HCl / acetone / 5 h / Heating 10: 87 percent / p-toluenesulfonic acid / 17 h / Heating 11: 95.8 percent / pyridine; ethanol / 22 h / Ambient temperature 12: 84.6 percent / 25percent (i-Bu)2AlH / benzene; hexane / 1.5 h / 0 - 5 °C 13: 77.9 percent / triethylamine / CH2Cl2 / 0.5 h 14: 57percent NaH / 1,2-dimethoxy-ethane / 18 h / Heating 15: 64.2 percent / KOH / H2O; methanol / 18 h / Heating 16: 84 percent / various solvent(s) / Heating 17: 90 percent / 2N HCl / acetone / 5 h / Heating 18: 94.9 percent / p-toluenesulfonic acid / 17 h / Heating View Scheme

1: 89 percent / p-toluenesulfonic acid / 8 h / Heating 2: CaCO3, Br2, sodium thiosulfate, LiBr, Li2CO3, p-toluenesulfonic acid 3: 84.1 percent / pyridine; ethanol / 22 h / Ambient temperature 4: 85.9 percent / 25percent (i-Bu)2AlH / benzene; hexane / 1.5 h / 0 - 5 °C / 1) 0-5 deg C, 1.5h, 2) 15 min 5: 86.2 percent / triethylamine / CH2Cl2 / 0.5 h / cooling 6: 90.6 g / dimethylformamide / 3 h / 70 °C 7: NaOH / methanol; H2O / 72 h / Heating 8: 63.3 percent / 2N HCl / acetone / 5 h / Heating 9: 87.3 percent / p-toluenesulfonic acid / 17 h / Heating View Scheme

1: 89 percent / p-toluenesulfonic acid / 8 h / Heating 2: CaCO3, Br2, sodium thiosulfate, LiBr, Li2CO3, p-toluenesulfonic acid 3: 84.1 percent / pyridine; ethanol / 22 h / Ambient temperature 4: 85.9 percent / 25percent (i-Bu)2AlH / benzene; hexane / 1.5 h / 0 - 5 °C / 1) 0-5 deg C, 1.5h, 2) 15 min 5: 86.2 percent / triethylamine / CH2Cl2 / 0.5 h / cooling 6: 1) 57percent NaH / 1) 1h, DME; 2) DME, 16h, reflux 7: KOH / methanol; H2O / 18 h / Heating 8: various solvent(s) / Heating 9: 2N HCl / acetone / 5 h / Heating View Scheme