1. General

If you were wait listed, you should make sure that you are enrolled by the end of the week (4/19/2010 at 5 pm). If not, please inform the instructor asap. You will not receive credit for the course, if you are not on the roster when it comes to assigning grades. Due to the fact that you will not be insured if an accident happens in the lab, you will be dismissed from the course immediately.


2. Experiment

Safety note: Diethyl ether is extremely flammable. Avoid any spills on the hot plate. The diethyl ether has to be evaporated in a warm water bath provided by the TA. Direct evaporation on the hot plate often causes fires! Do not forget to add a boiling stick when you evaporate off the diethyl ether to prevent it from foaming or bumping. If you cause a fire due to negligence, you will be dismissed immediately from class as a safety hazard.

In the initial stage of the experiment, a setting of 1-2 on the hotplate will provide enough heat for a gentle boiling. You do not want to evaporate the entire methanol. Make sure to place a watch glass with ice on the top. Why?

Do not add too much of the drying reagent to the ether solution. It will make it unnecessarily difficult to separate the liquid and the solid phase later. You will lose a significant amount of your product as well. Why?

The sodium borohydride bottle has to be closed after removing the amount of NaBH₄ needed. Why?

GC-MS is a very sensitive technique. Check on the web site for details (GC/MS). Dissolve only ~1-2 mg of your final product in 1 mL of diethyl ether. If you use significantly more, the column will be overloaded and all following sample runs will be difficult because the background signal increases. Make sure that you label your vial and write down the bar code number (last three digits) before you give it to your TA. The printout can (usually) be picked up in YH 3077E in the afternoon of the following day.


3. Critcial

a. How can you distinguish between camphor and isoborneol by IR spectroscopy?
b. Why is generally a fairly "broad melting point" observe for the final product?
c. Why do you get a mixture of isoborneol and borneol? Why is the mixture racemic?
d. How can you distinguish between borneol and isoborneol?
e. Why does the IR spectrum of borneol look very different when acquired in solid or the gas phase?