Indiana University Bloomington Organic Chemistry Questions

2. Draw the following compounds structure from their names (10pts)
a. 4-phenyl-2-nonene
b. isobutylcyclopentane
c. 3,4-dimethylhept-5-en-1-yne
d. 1-cyclohexylpropan-1-ol
e. 2-Penten-3-ol
f. (2R,3S)-2,3-dichlorononane
3. Mark any chiral center with an asterisk (*), label the functional groups present, and then
calculate the total possible number of stereoisomers. (10pts)
4. The following alkyl chloride can be prepared by addition of HCl to two different alkenes.
Draw the structures of both. (4pts)
5. Draw the following as line-bond structures, then determine if they represent stereoisomers,
constitutional isomers, or two identical molecules. (4pts)
CH3
Br
H3C
Cl
H
CH3
H3C
H
Br
H
H
Cl
6. For the following: (6pts)
a. First predict the products of the following reaction
CH3CH2O– + HCl Æ
b. Draw the mechanism using arrow pushing for the reaction
c. Label the following in your mechanism above: Lewis acid, Lewis base, conjugate
acid, conjugate base, nucleophile, and electrophile
7. The following reaction occurs following an SN2 mechanism. Draw the mechanism using
arrows then determine the chirality (S or R) of both the reactant and the product. (5pts)
8. The reaction from question 7 yields almost exclusively one enantiomer as the product,
while the SN1 reaction yields a racemic mixture. Explain why this occurs – draw the
mechanism of the SN1 reaction. (5pts)
9. Draw the mechanism for one example of the preparation of the following alcohol (5pts)
10. The following molecule is named incorrectly. Draw the structure, then give the correct
name. 4-secbutyl-3-methylheptane (4pts)
11. Draw two conformations of cyclohexanol (C6H11OH). Indicate axial and equatorial
positions. Calculate the formal charge of oxygen and label the more stable conformation.
(6pts)
12. Label the following as E, Z, R, or S anywhere that is necessary. (4pts)
13. Draw the mechanism for the reaction of propyne with NaNH2, followed by the addition
of CH3CH2CH2Br. (5pts)
14. Determine the structures of A – K (12pts)
15. Devise a synthesis for each compound, starting with methylenecyclohexane and any other
reagents you need. (10pts)
a. 1-methylcyclohexanol
b. Cyclohexylmethanol
c. 2-chloro-1-methylcyclohexanol
d. 1-(hydroxymethyl)cyclohexanol
e. 1-(phenylmethyl)cyclohexanol
11. Propose a mechanism for the following reaction. There may be more products are formed
than are shown here. You only need to explain the formation of the products shown.
(5pts)
16. Compound A is an optically active alcohol. Treatment with chromic acid converts A into
a ketone, B. In a separate reaction, A is treated with converting A into compound C.
Compound C is purified, and then it is allowed to react with magnesium in ether to give a
Grignard reagent, D. Compound B is added to the resulting solution of the Grignard
reagent. After hydrolysis of the initial product (E), this solution is found to contain
3,4dimethylhexan-3-ol. Propose structures for compounds A, B, C, D, and E. (5pts)
17. Label the following alcohols as primary, secondary, or tertiary. Then draw the product of
this molecule when reacted with PCC in CH2Cl2 (5pts).
18. Predict the product of acid catalyzed dehydration for the following diol. Does this
reaction have an intermediate? If so, is this intermediate important? Why or why not?
(5pts)
Extra Credit:
1. Draw (E)-7,10-dichloro-6-ethyl-5-phenyl-4-(2-bromopropyl)dec-2-en-8-yn-1-ol
2. Propose a mechanism for the reaction below. (up to 3pts)
3. How would you achieve the following reaction instead? (up to 3pts)
4. Draw an example of a primary, secondary, and tertiary radical (label them clearly).
Which is most stable? (up to 2 points)
5. To the best of your ability, draw the orbital overlap responsible for a triple bond. Label
any sigma and pi bonding. (up to 2 points)
6. What was your favorite part of this class? What changes would you suggest for future
semesters? (up to 3 pts)