1.1: sodium hydroxide; ethylene glycol / 4 h / 170 - 180 °C 1.2: pH 1 2.1: di-isopropyl ether / 6 h / 20 - 75 °C 3.1: hydrogenchloride / water; tert-butyl methyl ether / 0.5 h / 20 - 25 °C 4.1: BH3*S(CH3)2 / tetrahydrofuran / 1 h / 50 - 55 °C / Inert atmosphere 4.2: 0 - 5 °C 5.1: triethylamine / 4-(N,N-dimethlyamino)pyridine / dichloromethane / 6 h / 25 - 30 °C 6.1: sodium hydroxide / dimethyl sulfoxide / 0.17 h / 20 - 25 °C 6.2: 2 h / 50 - 55 °C View Scheme