1.1: potassium carbonate / acetone / 22 h / 60 °C / Inert atmosphere 2.1: water; sodium hydroxide / tetrahydrofuran; methanol; dichloromethane / 20 °C 3.1: thionyl chloride / chloroform / Inert atmosphere 4.1: triethylamine / dichloromethane 5.1: lithium diisopropyl amide / tetrahydrofuran / Cooling with ice 5.2: -78 °C 6.1: 1 h / Reflux 7.1: hydrazine hydrate / methanol / 1 h / Reflux 8.1: sulfuric acid / ethanol / 1 h / Reflux View Scheme