1.1: B-chloro-diisopinocampheylborane / tetrahydrofuran / 2 h / 0 °C / Inert atmosphere 2.1: diisobutylaluminium hydride / toluene; tetrahydrofuran / 3.5 h / -78 °C / Inert atmosphere 2.2: -78 - 20 °C 3.1: tetrabutyl ammonium fluoride / water; tetrahydrofuran / 4 h / 0 °C 4.1: triethylamine; hydrogen / platinum on carbon / methanol / 24.25 h / 20 °C 5.1: potassium tert-butylate / tetrahydrofuran / 0.75 h / 0 °C / Inert atmosphere 5.2: -15 - -10 °C / Inert atmosphere View Scheme

1.1: B-chloro-diisopinocampheylborane / tetrahydrofuran / 2 h / 0 °C / Inert atmosphere 2.1: diisobutylaluminium hydride / toluene; tetrahydrofuran / 3.5 h / -78 °C / Inert atmosphere 2.2: -78 - 20 °C 3.1: tetrabutyl ammonium fluoride / water; tetrahydrofuran / 4 h / 0 °C 4.1: triethylamine; hydrogen / platinum on carbon / methanol / 24.25 h / 20 °C View Scheme

1.1: B-chloro-diisopinocampheylborane / tetrahydrofuran / 2 h / 0 °C / Inert atmosphere 2.1: diisobutylaluminium hydride / toluene; tetrahydrofuran / 3.5 h / -78 °C / Inert atmosphere 2.2: -78 - 20 °C 3.1: tetrabutyl ammonium fluoride / water; tetrahydrofuran / 4 h / 0 °C 4.1: triethylamine; hydrogen / platinum on carbon / methanol / 24.25 h / 20 °C 5.1: potassium tert-butylate / tetrahydrofuran / 0.75 h / 0 °C / Inert atmosphere 5.2: -15 - -10 °C / Inert atmosphere 6.1: caesium carbonate / N,N-dimethyl-formamide / 3 h / 40 °C View Scheme