Stereochemistry, a subdiscipline of chemistry, involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation. An important branch of stereochemistry is the study of chiral molecules

1. Chapter 7 Stereochemistry

2. • 1. Which of the molecules below are chiral?
•
•
•
•
A.
B.
C.
D.
only II
only III
I and III
II and III

3. • 2. Which of the molecules below are chiral?
•
•
•
•
A.
B.
C.
D.
only I
I and III
II and III
I, II, and III

4. • 3. Identify the chiral compound(s) below.
•
•
•
•
A.
B.
C.
D.
only II
II and III
III and IV
I, II, and IV

5. • 4. Which of the following molecules are
chiral?
•
•
•
•
A.
B.
C.
D.
only II
only III
II and III
I, II, and III

6. 5.
How many stereogenic centers are there in the
following molecule?
A.
B.
C.
D.
only 1
two
three
four

7. 6. How many stereogenic centers are there in
the following molecule?
•
•
•
•
A.
B.
C.
D.
only 1
two
three
four

8. • 7. Give the configurations, respectively, of
the following two molecules.
•
•
•
•
A.
B.
C.
D.
R and R
R and S
S and S
S and R

9. • 8. Give the configurations, respectively, of
the following two molecules.
•
•
•
•
A.
B.
C.
D.
R and R
R and S
S and S
S and R

10. • 9. Which one of the following groups has the
highest rank as assigned by the Cahn-IngoldPrelog system for stereogenic carbons?
•
•
•
•
A.
B.
C.
D.
–CH=CH2
–CH2OH
–CH=O
–CH2SH

11. • 10. Give the configurations of carbons 1 and 2,
respectively, in the structure shown below.
•
•
•
•
A.
B.
C.
D.
R and R
R and S
S and S
S and R

12. • 11. What is the IUPAC name of the following
compound?
•
•
•
•
A.
B.
C.
D.
(2S, 3S)-2,3-dibromopentane
(2S, 3R)-2,3-dibromopentane
(2R, 3S)-2,3-dibromopentane
(2R, 3R)-2,3-dibromopentane

13. • 12. Which of the following statements are true?
I. If a molecule has a plane of symmetry it is achiral.
II. If a molecule has a center of symmetry it is achiral.
III. If a molecule has one stereogenic center it is chiral.
•
•
•
•
A.
B.
C.
D.
I and II
I and III
II and III
I, II, and III

14. • 13. What is the relationship between the
following two molecules?
•
•
•
•
A.
B.
C.
D.
identical
enantiomers
diastereomers
constitutional isomers

15. • 14. What are the configurations of carbons 2
and 3 in the Fischer projection below?
•
•
•
•
A.
B.
C.
D.
2R, 3R
2R, 3S
2S, 3R
2S, 3S

16. • 15. Compound X, C5H10O, is optically active. The compound consumes
one equivalent of hydrogen to give C5H12O. The hydrogenation product is
also optically active. Which compound below matches the information?
•
•
•
•
A.
B.
C.
D.
A
B
C
D

17. 16. A pure sample of (S)-phenylalanine has a
specific rotation of +70 . A mixture of the two
enantiomers of phenylalanine has a specific
rotation of +7.0 . What are the percentages of the S
and R enantiomers in the mixture?
•
•
•
•
A.
B.
C.
D.
95% S, 5% R
90% S, 10% R
55% S, 45% R
52.5% S, 47.5% R

18. • 17. How many stereoisomers are there for the
compound shown below?
•
•
•
•
A.
B.
C.
D.
two
four
six
eight

19. • 18. Give the total number of stereoisomers of
2,3-dibromobutane.
•
•
•
•
A.
B.
C.
D.
none, only a single structure
two
three
four

20. • 19. What is the relationship between the
following two compounds?
•
•
•
•
A.
B.
C.
D.
identical
enantiomers
diastereomers
constitutional isomers

21. • 20. What is the relationship between the
following two compounds?
• A. different conformations of the same
compound
• B. enantiomers
• C. diastereomers
• D. constitutional isomers