1.1: lithium hexamethyldisilazane / tetrahydrofuran / 1.5 h / -5 °C 1.2: 3.25 h / -5 - 20 °C 2.1: sodium hydroxide; water / tetrahydrofuran / 3 h / 50 °C 3.1: thionyl chloride; N,N-dimethyl-formamide / dichloromethane / 18 h / 25 °C 4.1: triethylamine / toluene / 2 h / -10 °C 5.1: dihydrogen peroxide; lithium hydroxide hydrate / methanol; water / 1 h / -10 °C 5.2: -10 - 20 °C View Scheme