1.1: N-bromosuccinmide / N,N-dimethyl-formamide / 0.5 h / 20 °C / Inert atmosphere 2.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0 - 20 °C / Inert atmosphere 2.2: 1 h / 20 °C / Inert atmosphere 3.1: toluene-4-sulfonic acid / toluene / 5 h / Inert atmosphere; Reflux 4.1: n-butyllithium / tetrahydrofuran / 0.5 h / -10 °C / Inert atmosphere 4.2: -40 - 20 °C / Inert atmosphere 5.1: sulfuric acid; dihydrogen peroxide; boric acid / methanol; water / 0.5 h / Inert atmosphere; Reflux 5.2: 20 °C / Inert atmosphere 6.1: hydrogen / methanol / 3 h / 20 °C / 3102.97 Torr View Scheme