1.1: acetic acid / 1 h / Reflux; Inert atmosphere 1.2: 0.5 h / 50 °C / Inert atmosphere 1.3: 1 h / 50 - 60 °C 2.1: sulfuric acid / ethanol / 0.25 h / 5 °C / Inert atmosphere 2.2: 1.5 h 2.3: 4 h / Reflux 3.1: magnesium / tetrahydrofuran / 60 °C / Inert atmosphere 3.2: 0.67 h / Inert atmosphere 4.1: lithium aluminium tetrahydride / tetrahydrofuran / 0 - 20 °C / Inert atmosphere View Scheme

1.1: sulfuric acid / ethanol / 0.25 h / 5 °C / Inert atmosphere 1.2: 1.5 h 1.3: 4 h / Reflux 2.1: magnesium / tetrahydrofuran / 60 °C / Inert atmosphere 2.2: 0.67 h / Inert atmosphere 3.1: lithium aluminium tetrahydride / tetrahydrofuran / 0 - 20 °C / Inert atmosphere View Scheme