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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.
The draft version of paper is due on 1-30-2004 at 5 pm in YH 1217. 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.
The third quiz will be on January 28, 2004 in lecture. Please make sure that you arrive on time.
1. You are going to use TLC during the epoxidation experiment .
a. Which purpose does this TLC serve in this experiment?
b. You are going to use to different visualization techniques. In which sequence do you use them and why? What do you expect to observe?
2. Referring to the epoxidation, answer the following questions.
a. Some of you will use pyridine N-oxide in addition to the catalyst. What is the function of this compound?
b. What is the source of the oxygen in the formation of the epoxide? Which other oxygen sources could you use with this catalyst?
c. Why is sodium phosphate solution used in this reaction?
3. What is the active species that serves as oxygen transfer reagent in this reaction?
4. The observed ee-values for many epoxidation reactions are significantly smaller than 100%. Rationalize this observation.