The reduction of cyclohexanone to cyclohexanol with sodium borohydride This reaction evolves hydrogen gas and should be carried out in the hood. Place a magnetic stir bar in a 100mL Erlenmeyer flask containing water (15 mL) and 10% aqueous sodium hydorxide (0.20 mL or about 3 drops). Cool the solution in an ice-water bath and while stirring add sodium borohydride (0.75 g, 0.02 mol). continue stirring and add cyclohexanone (4.9 g or 5.1 mL, 0.05 mol) dropwise while maintaining the temperature under 40 C. After the addition is complete (5 to 10 minutes), remove the ice bath and stir the solution for another 30 minutes. Continue stirring and slowly add 6M HCL (5mL). Hydorgen gas evolution may be vigorous, but can be controlled somewhat by the rate of addition of the acid.