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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 4-30-2004 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 April 27, 2004 in lecture. Please make sure that you arrive on time.
1. In the lab, various styrene derivatives are used as reactants for the epoxidation. The observed e.e.-values for the epoxides are around 40-70% usually. Rationalize this observation.
2. Which oxygen sources can be used for the epoxidation of an alkene when the Jacobsen catalyst is used?
3. Referring to the epoxidation reaction,
a. which purpose does this TLC serve in this reaction?
b. why is the a "Ceric staining solution" used in this experiment?
c. why is it important to main a stable pH-value for the reaction?
d Some of you will use pyridine N-oxide in addition to the catalyst. What is the function of this compound?
4. A student plans to use 1.5 g of styrene for his epoxidation. His procedure requires the use of 4 mole% of the Jacobsen catalyst and 1.5 equivalents of oxidant (bleach).
a. How many grams of the catalyst are needed?
b. What is the volume of bleach required in this experiment?
c. What else does he need to add to his mixture when he carries out the reaction?