Name______________________________
Chem 330 Final Exam Fall 2007
Part I:
1. (5 pts) Identify the sugar below, giving the name of the sugar, the type of ring, whether
it is D or L, whether it is alpha or beta, whether it is an acetal or a hemiacetal. Put an
asterisk on the carbon.that is the acetal or hemiacetal carbon. Put a box around the
carbon that indicates whether it is a D or an L sugar.
CH2OH
O
H
H
H
OH
OH
OH
OH
H
(8 pts) Draw the - and -chair forms of D-mannose. Label which is which.
O
O
D-mannose
Which of the two anomers would you expect to predominate in an equilibrium
mixture? Why?
3. (6 pts) Classify the sugar D-tagatose. Then draw -D-tagatofuranose.
4. (8 pts) Identify the two monosaccharides in the following structure. Is the
configuration of the left-hand monosaccharide  or ? Is this disaccharide a reducing
sugar or not?
___________________
_____________
5. (4 pts) The following amino acid played a role in a science fiction story about an alien
invasion.
CO2-
CH3S
a. Is this amino acid an a-amino acid? Yes No
O
NH3+
b. Would you expect this amino acid to be: non-polar or polar or acidic or basic
6. (12 pts) Draw the tripeptide phe-thr-glu at physiological pH (~ pH 7).
8. (8 pts) Draw the predominant forms of serine at pH 1.0, 6.0, and 11.0. Calculate the
isoelectric point (pI) of this amino acid if pKa1 and pKa2 are 2.00 and 10.60, respectively.
pH = 1.0
pH = 6.0
pH = 11.0
pI =
9. (6 pts). Calculate the iosoelectric point (pI) of lysine, given the following pKas: pKa1
=2.18, pKa2 = 8.95, and pKaR = 10.53
10. (5 pts) Explain why acid chlorides are the most reactive carboxylic acid derivative
and an amide is the least reactive..
11. (12 pts) Show how the acid chloride shown below could be converted to the products
shown. By each arrow, give the reagents that would accomplish each transformation:
O
C OH
O
O
O
C O
C Cl
C N
O
O
C O C
CH2CH3
12. (16 pts) Indicate how the following compounds could be synthesized using the
reaction indicated.
OH
C
CH2
a.
CH3
using a Grignard reaction
O
OH
usning an aldol reaction
b.
O
O
using a Claissen reaction
c. CH3O
13. (14 pts) Predict the product and give a detailed mechanism for the aldol condensation
of 2-methylbutanal in base. Show all resonance structures.
Part II: Comprehensive
1. (4 pts) Assign R or S to each chiral carbon in the following.
CHO
O
CH3
C H
CO2H
H C
H3C
CH2
H
OH
H
OH
CH2OH
2. (9 pts) Draw all equivalent resonance structures for the following OCN- anion,
including formal charges where appropriate. Indicate which resonance structure would be
expected to be the major resonance contributor and explain why.
OCN-
3. (10 pts) What are the hybridization and molecular geometries of each of the indicated
atoms in the compound shown below? Write the hybridization and molecular geometry
right by each arrow.
O
O
C
C
H
4. (2 pts) Circle the compound in each pair that would be the stronger acid
CO2H
or
CO2H
CO2H
Cl
F
or
CO2H
Cl
Br
5. (3 pts) Circle the compound in each pair that:
a. is the stronger acid:
HBr or
b. is the stronger acid
HIO3 or
c. is the better nucleophile:
For
HCl
HBrO3
I-
6. (6 pts) Draw the two chair conformations of tciss-1-tert-butyl-2-methylcyclohexane.
Indicate which conformation would be more stable.
7. (12 pts) Consider the following compounds and their
reactivity in SN1 and SN2 conditions::
Br
Br
Br
a. Which would react faster with H2O and heat? ____
b. Which would react faster with NaCN in DMSO? ____
c. Which would give the greatest amount of elimination
I
II
product with CH3ONa? ____
Using the compound you selected for each part a-c, write the product of each reaction
a
b
c
III
7. (4 pts) Indicate the relationship between the structures in the following pair
(constitutional isomers, enantiomers, diastereomers, or identical).
HO H
HO H
CH2CH3
H3C
H OH
H3C
CH3
CH2CH3
H
Br
Br
H3C
CH2CH3
HO H
CH2CH3
CH3
H
9. (6 pts) Circle the compounds below that are aromatic:
O
O
N
CH3
10. (8 pts) Write a detailed mechanism for the SN1 reaction of (S)-2-bromobutane with
propanol. Show all arrows. Clearly indicate the stereochemistry of the product. If more
than one product is formed, indicate the relationship between the products.
OH
CH3
CH3
11. (24 pts) Predict the major product(s) in each of the following reactions. Specify
stereochemistry where appropriate. Reactions need not be balanced.
Br2
CCl4 (solvent)
HBr
OH
K2Cr2O 7
H2SO 4
OH
H+
H2O
NaOH
Br
O
1)
MgBr
2) H3O+
O
CH3OH (excess)
H
H+
OH
H2SO 4
heat
O
O
OH
1) NaBH4
2) H3O +
12. (12 pts) Give a detailed mechanisms of the acid-catalyzed Fischer esterification of
ethanoic acid with methanol, including all resonance structures.
O
O
H+
CH3C OCH3 + H2O
CH3C OH + CH3OH
CH O
CH O
CH O
H
OH
HO
H
OH
H
OH
HO
H
OH
H
OH
H
OH
H
OH
H
OH
H
OH
H
OH
H
OH
CH2OH
OH
HO
H
OH
H
H
OH
H
CH2OH
H
CH2OH
CH O
CH O
OH
HO
H
H
HO
H
H
HO
H
HO
H
H
OH
CH2OH
CH2OH
OH
H
CH2OH
CH2OH
D-talose
CH2OH
CH2OH
O
O
H
H
OH
HO
H
H
OH
H
OH
HO
H
OH
H
OH
H
D-fructose
Nonpolar
Side Chains
OH
HO
H
H
HO
H
H
OH
OH
CH2OH
CH2OH
D-sorbose
CH2OH
D-tagatose
Polar
Side Chains
-
Acidic
Side Chains
-
CO2
HO
HO2C
NH3+
NH3
valine (val)
OH
-
CO2
HO2C
CO2
+
isoleucine (ile)
phenylalanine (phe)
threonine (thr)
NH3+
asparagine (asn)
NH
-
H2N
+
NH3+
arginine (arg)
H
CO2HO
+
NH3
tyrosine (tyr)
CO2
HN
glutamic acid (glu)
-
O
NH3+
lysine (lys)
-
CO2
H2N
-
CO2
H2N
CO2
NH3
NH3+
NH3+
CO2
NH3+
aspartic acid (asp)
serine (ser)
CO2-
Basic
Side Chains
-
CO2
+
OH
D-galactose
O
NH3
HO
HO
CH2OH
D-idose
CH2OH
D-psicose
H
OH
D-gulose
O
H
D-mannose
H
H
HO
HO
D-glucose
CH O
H
OH
CH2OH
D-altrose
CH O
H
H
CH2OH
D-allose
HO
H
CH O
N
N
CO2+
NH3
histidine (his)