Organic Chemistry Lab
8 March 2014
Project 4: Interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone
It is truly incredible how the smallest differences between molecules can lead them to react and behave entirely differently. These differences are perhaps most highlighted in the medical field where stereochemistry of a molecule can be the difference between having a medically active, effective drug and a toxic, potentially lethal, substance. For instance, one enantiomer of the molecule Naproxen is used to treat arthritis pain but the other enantiomer causes liver poisoning. With such high stakes, it is easy to see the importance of being able to create molecules in the exact way necessary to yield the desired effects. Therefore, it is necessary for synthetic chemists to have reagents that allow them to be selective in their manipulation of a molecule, be it in oxidation, reduction, or in the addition of a functional group. In this lab we will examine the stereoselectivity of the reduction of 4-tert-butylcyclohexanone (Figure 1) using sodium borohydride (Figure 2). In the first week of this lab we will use sodium hypochlorite
(Figure 3) to oxidize (Mechanism: Figure 6) commercial 4-tert-butylcyclohexanol, synthesizing
4-tert-butylcyclohexanone and using IR analysis to confirm that our oxidation was successful. In the second week of this lab we will use sodium borohydride to reduce (Mechanism: Figure 7) the
4-tert-butylcyclohexanone created the previous week into the cis-4-tert-butylcyclohexanol isomer (Figure 4), the trans-4-tert-butylcyclohexanol isomer (Figure 5), or a racemic mixture of
the two. We will then compare the isomeric composition of the product we yielded in week 2 to commercial 4-tert-butylcyclohexanol via NMR.
Figure 1. 4-tert-butylcyclohexanone
Figure 2. Sodium Borohydride
Figure 3. Sodium Hypochlorite
Cited: Mohrig, Jerry R., Christina N. Hammond, Paul F. Schatz, and Terence C. Morrill.Modern Projcts and Experiments in Organic Chemistry: Miniscale and Williamson Microscale. Second ed. N.p.: n.p., n.d. Print.