Chemistry 351 Laboratory - Spring Semester 2006

Expt #4. Oxidation of Borneol and Reduction of Camphor

Relevant textbook readings - Pavia, expt 28. Smith chap 12.2, 12.7, 12.12, 201-20.5

Prelab - Make sure you include the moles to be used of all reactants and the theoretical yields of the products. Make sure to bring your laptop to this lab.

Overview - You will oxidize a chiral alcohol, borneol (endo-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol) to the corresponding ketone, camphor (1,7,7-trimethylbicyclo[2.2.1]heptan-2-one) using sodium hypochlorite. The camphor product will be characterized by IR and mp determination. The ketone will be reduced back to an alcohol using NaBH₄ and we will observe the stereoselectivity of this reaction using ¹H NMR.  Molecular modeling will be used to explain the result.

Procedure - We are carrying out Experiment 28A, B, C  in Pavia on pp 270-277 as well as the optional molecular modeling on p 277. The following are modifications and other notes to keep in mind when carrying out the procedures. 

    1. The apparatus for Part A calls for an air condenser. Use a regular jacketed condenser but do not connect water tubes or run water through as one normally would do. 

    2. Use the dry film method (p 753) for the IR of the camphor product.

    3. I recommend using a screw cap vial in place of the 10-mL Erlenmeyer flask in the isolation of the first product.

    4. We will not obtain the IR spectrum of the final product. Instead a mp and ¹H NMR spectrum will suffice. 

Report:

Results. Make sure to integrate the NMR spectrum of the final product as described in the Part C procedure on p 277 and present these results, as well as the Camphor IR and mp data, in your results tables.

Assigned questions. Do numbers  2, 3, and 5 on p 278 of Pavia. 

Conclusions. Present and discuss the mechanism of each reaction carried out. Also Include discussions of...

• the yields obtained in each reaction and reasons for loss of yield
• the purity of the camphor product of the first step as indicated by IR and mp
• interpretation of the IR spectrum of camphor including peak assignments and a comparison to the literature spectrum
• the stereoselectivity of the hydride reduction step (part C - ¹H NMR results) including an explanation based on the molecular modeling exercise