cyclohexa-1,4-diene; palladium on activated charcoal in 1,4-dioxane; ethanol T=20°C; 0.25 h;

1: 90 percent / potassium carbonate / 24 h / Heating 2: 74 percent / DIBAL-H / toluene / 3 h / -78 °C 3: 88 percent / sodium borohydride; trifluoroacetic acid / tetrahydrofuran / 1 h / 0 - 20 °C 4: 80 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dioxane / 0.25 h / 20 °C View Scheme

1: 88 percent / sodium borohydride; trifluoroacetic acid / tetrahydrofuran / 1 h / 0 - 20 °C 2: 80 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dioxane / 0.25 h / 20 °C View Scheme

1: 74 percent / DIBAL-H / toluene / 3 h / -78 °C 2: 88 percent / sodium borohydride; trifluoroacetic acid / tetrahydrofuran / 1 h / 0 - 20 °C 3: 80 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dioxane / 0.25 h / 20 °C View Scheme

1.1: lithium diisopropylamide / tetrahydrofuran; hexane / 0.25 h / -78 °C 1.2: 69 percent / tetrahydrofuran; hexane / 0.83 h / -78 - 20 °C 2.1: 90 percent / potassium carbonate / 24 h / Heating 3.1: 74 percent / DIBAL-H / toluene / 3 h / -78 °C 4.1: 88 percent / sodium borohydride; trifluoroacetic acid / tetrahydrofuran / 1 h / 0 - 20 °C 5.1: 80 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dioxane / 0.25 h / 20 °C View Scheme