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004:121 Exam I Spring, 2002 February 20, 2002
Name (please print): _____________________________ Signature: ___________________
Student ID #: ______________________
Please check to make sure there are six pages (not including this cover page) in this exam booklet. There are a total of eight questions. Answer the questions in ink in the spaces provided. Use the backs of the
pages for additional space or scratch paper if needed. Remember no re-grades for RED ink or pencil. Also NO CHEATING!
Good Luck!
1. ____________
2. ____________
3. ____________
4. ____________
5. ____________
6. ____________
7. ____________
8. ____________
Total: _______________
- The following questions relate to the structures A-F below. Some questions may have more than
one correct answer (if so, give all of them). If there is no correct answer among the choices write “none”.
a. Which of the above contain(s) an ester group? __________
b. Which contain(s) a secondary amine (or amine derivative) group? __________
c. Which would give a strong absorbance peak(s) near 1700 cm-1^ in an IR spectrum? ________
d. Which would give absorbance peak(s) at 3600 cm-1^ in an IR spectrum? __________
e. Which compound(s) above would have a pKa = ~16? __________
f. Which compound above would be the most acidic? __________
g. Would compound C be a polar molecule? _________
h. Which compound(s) would undergo hydrogen-bonding and thereby affect boiling point and
other physical properties? _________
i. Which compound(s) would be a Bronsted acid? __________
j. The conjugate base of compound B would be mostly stabilized because of what? _________
k. The fluorine molecules in D make the oxygens less electron rich because of what effect?
____________________
OH
O
C
CH (^3)
CH (^3)
CH (^3)
H 2 N
O H
Br
F
F O
O
CH 3
N
H H
Cl C N
A
B
C
D
E F
c. 3,3-dimethyl-5-propylnonane
- One of the dramatic achievements of synthetic organic chemistry, and one that has had a
profound impact on history and human society, has been the development of “the pill”. Many of the different oral contraceptives in use today are synthetically modified steroids which interfere with the normal estrus or progestational cycle in women. An example of this is norethindrone, commonly know as Norlutin. Use the structure of Norlutin below to answer the following questions.
C
OH
CH
CH 3
H
O
a
c b
d
1 2
3 4
5 6
7
8
9 10
a. Write down all the functional groups that we have learned in class for this molecule. Spell them correctly!
b. The protons labeled a-d have varying pKa values. Estimate the correct value for each using the following list: 5, 9, 16, 19, 25, 38, 45, 50
a: __________ b:__________ c: __________ d: __________
c. What kind(s) of hybrid atomic orbitals overlap to form the bond between carbons 5 and 6?
_________
d. What type(s) of atomic orbitals are involved in the carbon-carbon “triple bond” shown above and what type of molecular orbitals are formed by them (be specific about what forms what)?
e. Using resonance forms show why the #5 carbon has a significant δ+^ associated with it. Make sure you show any formal charges that may be present with the structure (you only have to draw the two rings that are numbered to save time and space).
- Put the following molecules in order of increasing boiling point. (Lowest ‡ Highest)
H 3 C
CH 3
H 3 C CH 3
H 3 C CH 3
H 3 C
CH 3
H 3 C
H 3 C
CH 3
A B
C
D
List here:
What are the forces that are responsible for this trend? (Hint: It only takes a few words here, one
sentence max.)
- Draw the mechanism of the “substitution” reaction we went over in lecture, shown below. Make
sure to use the curved arrow formalism and be precise with your arrow pushing. Use the correct type of arrows as well. (Hint: The mechanism takes place in 3 steps, fill them in the spaces provided)
Step 1:
Step 2:
Step 3:
CH 3
H 3 C C
CH 3
Cl
CH 3
H 3 C C
CH 3
OH + HCl
H2O
+ H2O
