CHEM 2325
December 9, 2008
Exam 4
Name:
UTEP ID#:
1.-4. Match each structure to a common name below. Answers may be repeated.
O
HO
O
HO
OH
O
OH
1.
O
HO
OH
HO
2.
a. cellobiose
O
OH
OH
b. lactose
O
HO
OH
O
OH
OH
3.
c. maltose
O
HO
OH
4.
O
OH
OH
OH
HO
OH
O
HO
OH
HO
OH
O
HO
OH
HO
OH
OH
O
HO
OH
OH
d. sucrose
e. not a.-d.
d. [C(H2O)]n
e. not a.-d.
d. hemiacetal
e. not a.-d.
5. The molecular formula of the compounds in questions 1.-4. is?
a. C12H8O11
b. C12H22O11
c. C12H24O12
6. The compounds in questions 1.-4. do not contain a(n)?
a. acetal
b. anomeric carbon
c. glycoside
7. The structures in questions 2. and 3., above, are?
a. anomers
b. diastereomers but not epimers
c. enantiomers
d. epimers
e. not a.-d.
8. Which carbohydrate above becomes indigestible to many humans as they mature?
a. 1.
b. 2.
c. 3.
d. 4.
e. not a.-d.
9. Which carbohydrate should be used to make D-glucose by the Kiliani-Fischer synthesis? More than one
series of reactions may be necessary.
a. D-erythrose
b. D-threose
c. L-erythrose
d. L-threose
e. not a.-d.
10. Which carbohydrate should be used to make threose by the Ruff degradation? More than one series of
reactions may be necessary.
a. fructose
b. galactose
c. glucose
d. ribose
e. not a.-d.
11. Which intermediate is necessary to both the Kiliani-Fischer synthesis and the Ruff degradation?
a. carboxylic acid
b. cyanohydrin
c. iron carboxylate
d. lactone
e. not a.-d.
12. The sodium salt of erythorbic acid is an anti-oxidant/food preservative used in meats to keep them looking
red longer. Given that erythorbic acid is an epimer of Vitamin C (Ascorbic Acid) which can be made by
oxidation of D-glucose, which structure corresponds to erythorbic acid? (Hint: Structure a. is Vitamin C).
HO
HO
HO
O
HO
O
H
a.
HO
O
HO
HO
O
O
H
HO
OH
HO
b.
HO
O
H
OH
c.
HO
O
O
H
OH
HO
d.
OH
e. not a.-d.
13. Which structure is Lys-Leu?
O
H2N
O
OH
O
H2N
N
NH2
a.
O
H2N
H
O
OH
O
H2N
N
NH2
c.
H
d.
OH
N
NH2
b.
O
H
O
OH
N
NH2
H
e. not a.-d.
14. The reaction of 2-methylpropanal, ammonia, hydrogen cyanide, and water/acid catalysis makes racemic?
a. isoleucine
b. leucine
c. lysine
d. valine
e. not a.-d.
15. Which alpha-amino acid has a side chain that might couple to another alpha-amino acid if DCC is used
without protecting groups?
a. lysine
b. methionine
c. phenylalanine
d. valine
e. not a.-d.
The retake homework for Exam 4 is due Saturday, December 13, by 1 p.m. via
http://organic.utep.edu/quiz/, no excuses! These sheets will be available for you to pickup after 1:30 p.m. today
in PSCI 202. A copy of this exam will be available through http://organic.utep.edu/courses/2325/exams.
Please submit something ahead of time just in case the internet goes out.
Monday, December 15, will be your last chance to pickup (PSCI 202) and check your exam scantrons
for erasure errors. If you find an error, please email me the details of your finding so that I can check my copy
and correct your grade. Final grades will be posted by Wednesday, December 17, via
http://organic.utep.edu/courses/mygrades.htm.
Have a wonderful life!