Examination #2 - California State University, Northridge

Chemistry 333
Examination #2
June 24, 2014
Professor Charonnat
Name: _____________________________
Be certain that your examination has seven (7) pages including this one.
Put your name on each page of this examination booklet.
By putting your name on this examination booklet you agree to abide by
California State University, Northridge policies of academic honesty and integrity.
Molecular models are allowed for this examination. All electronic devices, including calculators,
are unnecessary and are not allowed.
Name: ______________________
1.
(25 points)
Draw the specific reagent(s) necessary to effect each of the following four (4) transformations.
If more than one reaction is involved in an answer, be certain to distinguish the individual steps clearly.
Specify the relative stoichiometry of all reagents, also.
A.
OH
CN
H3C
CH3
H3C
CH3
B.
CH3
CH3
Br
Ph
C.
H3C
C
C
CH3
H3C
CH3
D.
CH3
H3C
H3C
H3C
CH3
Br
Name: ______________________
2.
(25 points)
Circle the number that corresponds to the correct answer for each of the following five (5) questions.
A. The specific rotation of (+)-tartaric acid is +12.0o . The specific rotation of its enantiomer is
1. -12.0o
2. 0o
3. +24.0o
B. Which of the following compounds is achiral?
1. (1S,2S)-1,2-dibromocyclohexane
2. (1S,2R)-1,2-dibromocyclohexane
3. (1R,2R)-1,2-dibromocyclohexane
C. The hydrolysis of (S)-3-bromo-3-methyloctane yields an alcohol with
1. complete inversion of configuration
2. complete retention of configuration
3. racemization
D. Consider the reaction of 1-bromoheptane with sodium iodide in acetone. If one doubles the
concentrations of both the alkyl bromide and the sodium iodide, the reaction rate will
1. double
2. quadruple
3. remain the same
E. A stronger base makes an E1 reaction proceed at
1. a faster rate
2. a slower rate
3. the same rate
Name: ______________________
3.
(30 points)
State the relationship between each of the six (6) structures at the bottom of this page and the bicyclic
carbonyl compound 1 (identical, enantiomer, diastereomer, structural isomer, conformational isomer,
or not isomeric).
O
O
OH
H
1
O
O
O
O
O
HO
H
H
HO
O
H
HO
O
O
H
O
O
OH
OH
O
O
H
OH
H
Name: ______________________
4.
(20 points)
Answer both of the following questions precisely, succinctly, and with correct grammar.
A. Explain why the fluoride anion of potassium fluoride/18-crown-6 is more nucleophilic than the
fluoride anion of potassium fluoride, itself. Draw structural formulas and a reaction-energy diagram
to illustrate your answer.
potential
energy
reaction progress
B. Why is the tosylate anion an especially good leaving group for nucleophilic substitutions?
Draw detailed structural formulas of this anion to illustrate your answer.
Name: ______________________
5.
(10 points)
Use IUPAC nomenclature to write the systematic name of the following alkene.
H3C
H3C
H3C
6.
CH3
(20 points)
Draw the mechanism of the following reaction, using the curved-arrow notation to indicate the
reorganization of electron density. Denote all lone pairs, nonzero formal charges, countercharges,
and reversibility or irreversibility. Depict the mechanism by drawing a three-dimensional conformation
to show why only the alkene 1 is obtained. Explain clearly why the isomeric alkene 2 is not formed.
CH3
CH3
Br
-
t-BuO K+
CH3
CH3
1
CH3
CH3
2
+
t-BuOH
+
+ K Br
-
Name: ______________________
7.
(20 points)
State whether each of the following reactions is non-enantioselective, partially enantioselective,
completely enantioselective, non-diastereoselective, partially diastereoselective, and/or completely
diastereoselective. If relevant, state if these reactions are enantiospecific and/or diastereospecific.
Describe your reasoning clearly and succinctly.
H3C
H3C
C
+
N
N
H3C
-
O
O
CH3
H3C
CH3
(racemic)
CH3
H3C
H3C
C
+
N
N
H3C
-
O
O
H3C
CH3
(racemic)
Congratulations!
1
2
3
4
5
6
7
Total:
/25
/25
/30
/20
/10
/20
/20
/150

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