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Problems Set #6
ATTN: answers to the below questions are due at the start of your lab period of Meeting 6; these answers should be part of your pre-lab write-up.
Announcements:
1. The next quiz will be on February 1, 2007 at 12 pm. The material covered will include the catalyst synthesis, the epoxidation and the theoretical aspects.
2. The draft version of paper is due on 2-2-2007 at 5 pm. The draft version is worth 15 points, the final paper 45 points. For more information what the draft is supposed to contain see here. Late submission will receive less credit. The more of your work you submit here, the more feedback you will get, which will beneficial for the final version. We will try to return the reports by Monday.
1. Referring to the epoxidation reaction carried out in the lab, answer the following questions.
a. How is the reaction time optimized in this reaction?
b. TLC is used to monitor the reaction and to optimize the solvent mixture for the flash chromatography step. Why does the procedure ask to aim for Rf-values of ~0.4-0.5 for the epoxide and ~0.8 for the alkene, respectively?
c. How is the alkene and the epoxide visualized in the TLC experiment? Outline a brief procedure.
d. Why is it important to do the work-up immediately after the reaction is completed?
e. Why is hexane added after the reaction is completed?
Do the following exercise and turn in it to the instructor by January 29, 2007 at 5 pm.
http://www.library.ucla.edu/sel/instruct/course/ch30cl/CH30CLjrns06.pdf