CHE 2202, Section 101 Spring 2014 Exam IIA Name: Honor Pledge

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CHE 2202, Section 101
Spring 2014
Exam IIA
Name: _____________________________________________________________________
Honor Pledge: I pledge on my honor that I have not violated the Appalachian State University
Academic Integrity Code. I will not discuss this exam with any students who have not yet taken
it.
Signature: _________________________________________
Unsigned honor pledges will result in a grade of 0 points.
Page 1: _____/ 12 points
Page 2: _____/ 18 points
Page 3: _____/ 42 points
Page 4: _____/ 12 points
Page 5: _____/ 14 points
Total: _____/ 100 points
0
1. (4 points) Which of the following molecules cannot be oxidized using Dess-Martin
periodinane in CH2Cl2? Circle the correct answer.
2. (3 points) Below is a reaction coordinate diagram of the nitration of benzene.
Using this same reaction coordinate diagram, compare the nitration of benzene to ethylbenzene
by drawing a dashed line (-----) to illustrate the reaction pathway for ethylbenzene.
3. (5 points) Using appropriate resonance structures, explain the meta-directing deactivating
character of benzoic acid.
/ 12 points
1
4. (4 points) Below are four steps, three of which are part of the mechanism of a typical
electrophilic aromatic substitution, and one of which is not. Put the three steps of the mechanism
in order by writing 1, 2, or 3; identify the step that is not part of the mechanism by writing n/a.
_____ Electrophile generation by coordination to an acid.
_____ Deprotonation and re-aromatization
_____ Nucleophilic attack of the pi electrons of the aromatic ring.
_____ Coordination of the acid to the aromatic ring.
5. (4 points) Rank the following by their reactivity in nucleophilic aromatic substitution. 1 =
most reactive, 4 = least reactive.
6. a. (4 points) Use curved arrows to illustrate the formation of benzyne in the following
reaction.
b. (3 points) Benzyne is much higher in energy than 2-carboxylbenzenediazonium, yet this
reaction is very exergonic and favorable. What drives this reaction forward?
c.) (3 points) Benzyne has never been isolated, yet we know it does form. How have chemists
determined that it is indeed formed, if only fleetingly?
2
/ 18 points
7. (42 points) Fill in the boxes with the missing reactants, reagents, or major products for each reaction.
If the reaction will not occur, write “no reaction” in the box.
/ 42 points
3
8. Draw mechanisms to illustrate the following transformations.
a. (6 points)
b.) (7 points)
/ 13 points
4
9. (7 points)How would you prepare the following target compound from benzene?
10. (8 points) Devise a synthetic route to the target below using starting materials from the
chemical bank, and any transformation that we have learned. Note: you will not use all the
chemicals from the chemical bank!
5
/ 15 points
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