1.1: sodium hydroxide; water / dichloromethane / Cooling with ice 2.1: 2-methyl tetrahydrofuran / 22 °C 3.1: 2,2,6,6-tetramethyl-piperidine; n-butyllithium / hexane; tetrahydrofuran / -78 - -70 °C / Inert atmosphere 3.2: -20 °C / Inert atmosphere 4.1: hydrogenchloride; water / isopropyl alcohol / 6.5 h / 45 °C View Scheme

water; sodium hydroxide in dichloromethane Cooling with ice;