tetrabutyl ammonium fluoride in tetrahydrofuran T=4°C; 16 h;

tetrabutyl ammonium fluoride; lithium triethylborohydride 1.) THF, room temperature, 2.) 2.5 h; Multistep reaction;

1: 97 percent / Et3N / CH2Cl2 / 3 h / 20 °C 2: LiBHEt3 / tetrahydrofuran / 2.5 h / 4 - 20 °C 3: 3.70 g / n-Bu4NF / tetrahydrofuran / 16 h / 4 °C View Scheme

1: 1.) triethylamine, 2.) imidazole / 1.) dichloromethane, 12 h, 2.) DMF, room temperature 1.5 h 2: lithium borohydride / tetrahydrofuran / 16 h 3: triethylamine / CH2Cl2 / 15 h 4: 1.) lithium triethylborohydride, 2.) tetra-n-butylammonium fluoride / 1.) THF, room temperature, 2.) 2.5 h View Scheme

1: lithium borohydride / tetrahydrofuran / 16 h 2: triethylamine / CH2Cl2 / 15 h 3: 1.) lithium triethylborohydride, 2.) tetra-n-butylammonium fluoride / 1.) THF, room temperature, 2.) 2.5 h View Scheme

N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium in tetrahydrofuran 1.) -78 to -46 deg C, 2 h, 2.) -78 deg C; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: 1.) triethylamine, 2.) imidazole / 1.) dichloromethane, 12 h, 2.) DMF, room temperature 1.5 h 2: lithium borohydride / tetrahydrofuran / 16 h 3: triethylamine / CH2Cl2 / 15 h 4: 1.) lithium triethylborohydride, 2.) tetra-n-butylammonium fluoride / 1.) THF, room temperature, 2.) 2.5 h View Scheme

1: triethylamine / 1,4-dioxane; water / 0 - 20 °C 2: 1H-imidazole / N,N-dimethyl-formamide / 1.5 h / 20 °C / |Inert atmosphere 3: lithium borohydride / tetrahydrofuran / 0 - 20 °C / |Inert atmosphere 4: triethylamine / dichloromethane / 0 °C / |Inert atmosphere 5: lithium triethylborohydride / tetrahydrofuran / 2 h / 20 °C / |Cooling with ice; |Inert atmosphere 6: tetrabutyl ammonium fluoride / tetrahydrofuran / |Inert atmosphere View Scheme

1: 1H-imidazole / N,N-dimethyl-formamide / 1.5 h / 20 °C / |Inert atmosphere 2: lithium borohydride / tetrahydrofuran / 0 - 20 °C / |Inert atmosphere 3: triethylamine / dichloromethane / 0 °C / |Inert atmosphere 4: lithium triethylborohydride / tetrahydrofuran / 2 h / 20 °C / |Cooling with ice; |Inert atmosphere 5: tetrabutyl ammonium fluoride / tetrahydrofuran / |Inert atmosphere View Scheme