Week 3 Problem Set - 30BL

1.Using PC Spartan at the Science Learning Center (4 Floor Young Hall) do the following:

a. Draw camphor if you have not done it yet. Minimize the structures by clicking the minimize icon, , then save.

b. Go to the view mode by clicking the view icon, . Once in the view mode, click the Model menu and select Tube.

c. Select Calculations from the Setup menu.

The following window should appear. Select the options shown.



Verify the Charge is Neutral and Multiplicity is Singlet. Click OK.

• Select Submit from Setup menu.

  
  

  Under the Setup menu, select Surfaces. A window should appear. In this window click Add.

  

  A second window should appear. In this window, select the following

  

  Then click OK to exit dialog. Close the previous window.

  Select Submit from Setup menu. When the calculation is completed you will be notified.

  Under the Display menu, select Surfaces.

  

  A window should appear. In this window check the yellow box.

  

  Next, select the molecule by clicking on it. In the bottom right corner of the window, change the selection from Solid to Transparent.

d) Do the same (steps a-c) for 2-norbornanone.

2. Referring to the below reaction,

(endo/exo huh?)

answer the following questions:

a) which isomer is expected to be the major product? why? (use the include the LUMO diagram generated in question 1 to answer this question)

b) which product results from the exo approach of the hydride source?

c) which product would you obtain if you would use NaAlD₄ and CD₃OH as reagents?

3. Referring to the below reaction,

answer the following questions:

a) draw the endo and exo product formed

b) which product is the major and which is the minor? Explain using the LUMO generated above (include the diagram).

4. Referring to the reduction of camphor answer the following questions.

a. Sodium borohydride is used in a 16-fold excess in this reaction. Explain briefly why.

b. Would water or diethyl ether be good solvents in this reaction?

5. Referring to the vacuum filtration performed in this experiment, draw two sketches showing the side view and the top view of the setup. Label all parts.

6. A student reacts iso-butanol with conc. sulfuric acid at 130 ^oC. After an aqueous work-up, she distills the mixture and obtains a GC-chromatogram of the distillate using a polar GC column.

a. The GC print-out shows two peaks total at 2 min (Area=300 units²) and 5 min (Area=15 units²). Which conclusion can be made about the composition of the mixture? Assume that the response factors are the same for both compounds.

b. How could she identify the compounds using GC chromatography only?

7. Why do you isolate a racemic mixture of isoborneol in your experiment? What would be the specific optical rotation [a]_D of this mixture?