1: CaCO3 / N,N-dimethyl-acetamide / 2 h / Heating 2: 2.47 g / aq. KOH / methanol / 10 h / Heating 3: 85 percent / CrO3; aq. H2SO4 / 1 h / 50 °C View Scheme

1.1: O3 / methanol; CH2Cl2 / 2 °C 1.2: Me2S / methanol; CH2Cl2 / 16 h / 20 °C 1.3: 67.8 percent / TsOH / CH2Cl2 / 16 h / 20 °C 2.1: 98 percent / KOH / ethanol / 2 h / Heating 3.1: 86 percent / diethyl ether / 0 - 20 °C 4.1: 80 percent / pyridine / 48 h / 2 - 20 °C 5.1: SOCl2 / 0.5 h / 65 - 70 °C 6.1: Br2 / SOCl2 / 5 h / 60 °C 7.1: 6.79 g / 2 h / Heating View Scheme

1: 86 percent / diethyl ether / 0 - 20 °C 2: 80 percent / pyridine / 48 h / 2 - 20 °C 3: SOCl2 / 0.5 h / 65 - 70 °C 4: Br2 / SOCl2 / 5 h / 60 °C 5: 6.79 g / 2 h / Heating View Scheme

1: 98 percent / KOH / ethanol / 2 h / Heating 2: 86 percent / diethyl ether / 0 - 20 °C 3: 80 percent / pyridine / 48 h / 2 - 20 °C 4: SOCl2 / 0.5 h / 65 - 70 °C 5: Br2 / SOCl2 / 5 h / 60 °C 6: 6.79 g / 2 h / Heating View Scheme

1: 80 percent / pyridine / 48 h / 2 - 20 °C 2: SOCl2 / 0.5 h / 65 - 70 °C 3: Br2 / SOCl2 / 5 h / 60 °C 4: 6.79 g / 2 h / Heating View Scheme

1: SOCl2 / 0.5 h / 65 - 70 °C 2: Br2 / SOCl2 / 5 h / 60 °C 3: 6.79 g / 2 h / Heating View Scheme

2 h; Heating;

1: CaCO3 / N,N-dimethyl-acetamide / 2 h / Heating 2: 2.47 g / aq. KOH / methanol / 10 h / Heating View Scheme