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How To Reduce 4-Tert-Butylcylohexanone

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In this experiment, sodium borohydride will be used to reduce 4-tert-butylcylohexanone into two 4-tert-butycycohexanol diastereoisomers with differing stereochemistry. Sodium borohydride is preferred over lithium aluminum hydride as a reducing reagent due to its “weak reducing agent” property. Using sodium borohydride allows for a more selective reduction around other functional groups, such as if you had a molecule that contains a carboxylic group and acetone, sodium borohydride will only reduce the ketone since it doesn’t have the capability of reducing the acid. The 4-ter-butylcyclohexanol diastereoisomers products were isolated by a liquid-liquid extraction involving dichloromethane in order to separate the organic and aqueous layer.
The purpose of this experiment is to establish the facial selectivity of the following reduction through analysis of the NMR usiing the identity and percent of each steroisomerstereoisomer present and calculating the ratios of the products. The reaction’s progress was tracked using TLC analysis and IR spectrum was taken to ensure the desired product is achieved.
During the experiment, when the addition of the sodium borohydride, the reducing agent, was added, the solution became a foggy white shade. When the 1.0mL of 0.05 HCl were …show more content…

This is due to the fact that the hydride more readily “attacks” from the axial direction, making the equatorial alcohol the major product, hence trans-4-tert-butylcyclohexanone. Sodium borohydride is not a sterically hindered reducing agent and can attack the 4-tert-butylcylohexanone from the top. Overall, this gives the more energetically stable

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