1.1: dimethylsulfide borane complex / tetrahydrofuran / 6 h / 0 °C / |Inert atmosphere; |Reflux 2.1: sodium carbonate / dichloromethane; water / 8 h / |Reflux 3.1: dichloromethane; dimethyl sulfoxide / 1 h / -78 °C / |Inert atmosphere 3.2: 0.25 h / 20 °C / |Inert atmosphere 4.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / 0 °C / |Inert atmosphere 4.2: 48 h / 0 °C / |Inert atmosphere 5.1: sulfuric acid / tetrahydrofuran; water / 12 h / |Reflux 6.1: sodium tetrahydroborate / methanol / 1 h / 0 - 25 °C View Scheme