1.1: hydrogenchloride / methanol; water / 0 °C / |Inert atmosphere 2.1: sodium carbonate / ethanol / 24 h / 85 °C / |Inert atmosphere 3.1: potassium tert-butylate / tetrahydrofuran / 2 h / 0 °C / |Inert atmosphere 4.1: n-butyllithium; diisopropylamine / tetrahydrofuran; hexane / 1 h / -78 - 0 °C / |Inert atmosphere 4.2: 1 h / -78 °C / |Inert atmosphere View Scheme