CHEM 2325
Exam 4
August 4, 2014
Name:
UTEP ID:
1.-5. Match each synthesis on the left to its name on the right. Answers may be repeated.
1.
2.
3.
4.
5.
Synthesis of a carbohydrate from a smaller carbohydrate
Synthesis of a carbohydrate from a large carbohydrate
Synthesis of an alpha-amino acid from an aldehyde
Synthesis of an alpha-amino acid from a carboxylic acid
Synthesis to isolate an alpha-amino acid derivative from a polypeptide
a. Edman
b. Fischer
c. Ruff
d. Strecker
e. not a.-d.
6. Given the following starting material, 3 intermediates, and product in a carbohydrate synthesis; which structure is
the last intermediate before the final product? Not all the intermediates of the synthesis may be shown.
O
O
O
Fe
O
a.
O
OH OH
OH
b.
H
H
H
HO
OH
+
O
OH
OH
O
OH
c. OH OH
d.
H
H
H
HO
OH
OH
OH
O
OH
e.
OH OH
OH
7. What reagent is used to transform the starting material to the first given intermediate in question 6?
a.
+
3+
b. Fe
Br2
c. heat
d.
H3 O
e. not a.-d.
8. The starting material of the synthesis of question 6 is a derivative of?
a. erythrose
b. glyceraldehyde
c.ribose
d. threose
e. not a.-d.
d. -pyranose
e. not a.-d.
9. The product of the synthesis of question 6 is a(n)?
a. -furanose
b. -pyranose
c. -furanose
10. Given the following starting material, 3 intermediates, and product in a carbohydrate synthesis; which structure is
the last intermediate before the final product? Not all the intermediate of the synthesis may be shown.
N
O
OH
O
H
OH
H
OH
a. HO
H
b.
OH
HO
c.
H
OH
H
HO
OH
O
OH
d. OH OH
O
e. OH OH
11. What reagent is used to transform the third intermediate to the final product of question 10?
+
a. H
+
b.
H3 O
c.
HCN
Na(Hg)
e. not a.-d.
d. threose
e. not a.-d.
d. L
e. not a.-d.
d.
12. The product of the synthesis of question 10 is a derivative of?
a. erythrose
b. glyceraldehyde
c.ribose
13. The product of the synthesis of question 10 is?
a. d
b. l
c. D
O
14. Which compound still exhibits optical rotation when treated with sodium borohydride but when degraded to a
smaller carbohydrate and treated with nitric acid, the new compound does not rotate plan polarized light?
O
O
O
HO
H
H
HO
H
HO
H
H
HO
H
HO
H
HO
OH
a.
OH
HO
OH
b.
O
H
H
OH
OH
H
OH
H
HO
OH
c.
H
OH
d.
e. not a.-d.
15. Which compound is -lactose?
O
HO
O
HO
OH
O
OH
HO
O
HO
OH
OH
a.
O
OH
HO
O
HO
OH
O
HO
OH
OH
b.
OH
O
HO
O
HO
O
HO
OH
O
HO
OH
c.
OH
OH
OH
O
OH
OH
HO
OH
d.
OH
OH
e. not a.-d.
OH
16. Which functional group does not form a silvered mirror when reacted with Ag+ in aqueous ammonia?
O
a. R
HO
H
b.
OH
R
HO
H
c.
R
OR'
R'O
H
d.
OR'
R
H
e. not a.-d.
17. Given the following starting material, 3 intermediates, and product in an amino acid synthesis; which structure is the
last intermediate before the final product? Not all the intermediates of the synthesis may be shown.
N
H
N
OH
a.
H
N
CO2H
b.
c.
N
O
H2N
H
d.
CN
e.
18. Which structure is Ile-Leu?
O
O
N
a.
N
NH2 H
CO2H
NH2 H
O
b.
CO2H
HO2C
c.
N
H
O
HO2C
NH2
N
H
d.
NH2
e. not a.-d.
19. The following reactions would give which product after removing the blocking groups from C?
O
O
O
OH +
+
Cl
O
NH2
a. structure 18. a.
H
OH + CH3OH
A
B
NH2
,
b. structure 18. b.
A
,
c. structure 18. c.
+
B
d. structure 18. d.
DCC
C
+
DCU
e. not a.-d.
20. What would be the byproduct of the reaction of structure 18.c. with phenylthioisocyanate and trifluoroacetic acid?
O
O
OH
a.
NH2
O
OH
b.
NH2
O
OH
c.
NH2
OH
d.
NH2
e. not a.-d.
The Exam 4 retake homework is due Tuesday, August 5, before 12:00 noon via http://organic.utep.edu/quiz. You may
work together on this homework but everyone is responsible for submitting his or her own answers via the online form
and you should not consult with anyone outside of class. Turn in your homework as long before the due date and time
as possible. No excuses for late entries!