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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 1-28-2005 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 27, 2005 in lecture. Please make sure that you arrive on time.
1. Referring to the epoxidation reaction,
a. which purpose does this TLC serve in this reaction?
b. what happens if the pH-value drops below 9.5 in the reaction? How is the pH-value stabilized?
c. which parameter determine the rate of the reaction in this case?
d. Why is hexane added during the work-up?
e. How are the alkene and teh epoxide visualized in the TLC experiment?
2. A student plans to use 1.0 g of 4-chloromethylstyrene 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?
3. The epoxidation of the 4-methyl cinnamic ethyl ester yields mainly the cis epoxide, while the epoxidation of 4-nitro cinnamic ethyl ester mainly affords the trans isomer. Rationalize this observation.