DEPARTMENT OF CHEMISTRY
3. Which of the following terms best describes the following pair of
molecules?
School of Physical & Mathematical Science, University of Ghana
FIRST SEMESTER
STEREOCHEMISTRY
CHEM 233 ASSIGNMENT
2023/2024
1. How many stereocenters (not including any N centers) are there in
morphine, whose structure is shown below?
a.
Isomers.
b.
Constitutional isomers.
c.
Configurational isomers.
d.
Geometric isomers.
4. What is the relationship between the two groups in the following
molecules?
2. Will an equal mixture of the following two molecules cause a net
rotation of plane-polarized light? (Assume that the molecule on the
right will rotate light.)
a.
Yes.
b.
No.
c.
This cannot be determined with the information given.
They are equatorial to one another.
b.
They are axial to one another.
c.
They are cis to one another.
d.
They are trans to one another.
5. Which group on the atom marked with an asterisk (*) has the highest
priority in the molecule below?
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a.
c. E.
d. Z.
8. In the molecule below, how many stereocenters have an S orientation?
a.
The alcohol.
b.
The chlorine.
c.
The ethyl group.
d.
The carboxylic acid group.
6. What is the spatial orientation of the double bond in the molecule below?
a.
Zero (0).
b.
One (1).
c.
Two (2).
d.
Three (3).
9. What is the complete name of the molecule below, if the base name of
the molecule is 3-bromo-5-isopropylcyclohexene?
a.
Cis.
b.
Trans.
c.
E.
d.
Z.
7. What is the spatial orientation of the stereocenter marked with an
asterisk (*) in the molecule below?
a. R.
b. S.
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a.
(3,R)-bromo-(5,R)-isopropyl-Z-cyclohexene.
b.
(3,S)-bromo-(5,S)-isopropyl-Z-cyclohexene.
c.
(3,S)-bromo-(5,R)-isopropyl-E-cyclohexene.
d.
(3,S)-bromo-(5,R)-isopropyl-Z-cyclohexene.
10. What is the stereochemical relationship between the following two
molecules?
levorotary
of R configuration
dextrorotary
of S configuration
13. The specific rotation of a compound is denoted by the symbol:
R
S
a.
identical
b.
Enantiomers.
c.
Diastereomers.
d.
None of the above.
[ ]D
14. Assign R or S configuration to the chiral carbon marked with an
asterisk
11. What is the stereochemical relationship between the following two
molecules?
R
S
a.
Identical.
b.
Enantiomers.
c.
Diastereomers.
d.
None of the above.
15. Assign the correct term describing the relationship to the following
two isomers:
12. Optically active molecules which rotate plane-polarized light in a
counterclockwise direction are said to be:
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a.
is levorotary
b.
rotates plane-polarized light in a counterclockwise direction
c.
rotates plane-polarized light in a clockwise direction
d.
is racemic
18. Would the following compound have an enantiomer:
enantiomers
diastereomers
identical
16. How many stereoisomers of S-Adenosylmethionone are possible in
principle (Free Hint: there are 5 stereogenic
centers):
Yes
No
19. Is the following compound meso:
8
16
Yes
32
No
None of the Above
20. Does the following compound rotate plane-polarized
light:
17. (R)-(+)-Glyceraldehyde:
Yes
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b. Is the molecule chiral? _____
c. Does it have a plane of symmetry? _____
d. Is it optically active? _____
e. Is it a meso compound? _____
No
CH 3 CH 2
CH 2CH 3
21. Label each asymmetric carbon with R or S.
H
H
23. A racemic mixture of 1-phenyl-2-propanamine can be resolved using
malic acid whose structures are shown below.
Malic acid
1-phenyl-2-propanamine
The two compounds undergo acid base reaction to form salt. Fill in the
boxes or the circles with the correct structure and configuration of the
enantiomers and the diastereomers.
22. Consider the molecule at right, and answer each of the questions about
it.
a. Is it superimposable on its mirror image? _____
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25. Arrange these compounds in order of increasing boiling point
a). Heptane
b). 1,5-Pentanediol
c). 1-Hexanol
26. Arrange these compounds in order of increasing solubility water
a). 1-Butanol
b). 1-Propanol c). 1,2-Dichloroethane
27. How would you prepare the following compounds from 2-methyl-1propanol
A. (CH3)2CHCH2Br
B. (CH3)2C=CH2
C. (CH3)2CHCH=O
D. (CH3)2CHCO2H
E. (CH3)2CHCH2OCOCH3
F. (CH3)2CHCO2C2H5
28. How would you distinguish among the following alcohols?
Ethanol, 2-propanol and 2, 2-dimethyl-1-propanol
24. Give the IUPAC names of the following indicating stereochemistry
where necessary. State the type of alcohol (Eg. Primary etc)
c). (C2H5)2C(CH3)CH2OH d). (CH3)2CH]2CHOH
f). (CH3)3C(CH2)3OH g). (CH3CH2CH2)2CHOH
h). CH3CH2CH2CH(CH3)CH2CH2OH
e). (C2H5)3COH
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