Chem 212
Survey of Organic and Biochemistry
Spring 2007
_____________________________
Print your full name legibly in the space above.
Exam 2: Ch. 6-10
22 March 2007
Instructions:
1. If you leave the room for any reason you may not return to continue the exam.
2. No books, notes, or calculator of any kind are permitted (including cell phones.) You may borrow a model kit.
3. Put all your answers on this exam paper. If you want something graded which is written on scratch paper, you must
indicate so in the regular space for the answer.
Good Luck!
1. (5 pts) Mark each stereocenter in the following molecules with an asterisk (*)
OH
O
OH
HO
SH
Br
Br
Br
OH
HO
HO
OH
2. (6 pts) Assign priorities to the groups in each set:
a. –C(CH3)3
–CH2Br
–CHO
–CH2CH(CH3)2
b.
–C6H5 (phenyl)
–C≡CH
-CH2OH
–Br
c.
–NH2
–CH2CCl3
–CH2CH2CBr3
–OH
3. (5 pts) For each of the following tetrahedral centers with priorities shown, assign the
chirality designation as either R or S:
3
1
3
2
4
3
2
4
3
1
4
1
2
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2
3
1
4
4
1
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Chem 212
Survey of Organic and Biochemistry
Spring 2007
4. (5 pts) Assign the chirality (R or S) for each of the chiral centers in the following
molecules.
H3C
CH2
NH2
S
CH3
OH
N
O
O
CH3
CH3
O
O
HO
5. (12 pts) Write the products of the acid-base reactions for each of the following, then
circle the side favored at equilibrium and calculate the equilibrium constant (may be
written as 10x.x). Refer to the table provided for pKa values.
a. CH3COOLi + C6H5OH
b. KOH + HC≡CH 
c. CH3OH + HNO3 
d. HCOONa + NH4Cl 
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Chem 212
Survey of Organic and Biochemistry
Spring 2007
6. (3 pts) Write the appropriate formula or structure for:
a. The conjugate acid of Na2CO3
b. The conjugate base of CH4
c. The conjugate acid of HSO4-
7. (9 pts) The following graph is a titration curve for 2-aminopropanoic acid. Based on this
information, draw the structures of 2-aminopropanoic acid that would predominate at each of
the three different pH values given below.
14
13
12
11
10
9
pH
8
7
6
5
4
3
2
1
0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
NaOH (mL)
pH = 2.0
pH=7
pH=12.5
8. (2 pts) Referring to the table in question 7, estimate the pKa of the less acidic group.
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Chem 212
Survey of Organic and Biochemistry
Spring 2007
9. (6 pts) Classify each of the following amines using all terms that apply from among the
following list: primary, secondary, tertiary, quaternary, aliphatic, aromatic, heterocyclic.
H3C
N
CH3
NH2
NH
CH3
+
NH
H3C
N
CH3
NH2
10. (6 pts) In certain bacterial infections, (CH3)3NH+ Cl- is produced. A clinical test for the
presence of this substance (and confirmation of the bacterial infection) is performed by
adding a drop of sodium hydroxide solution to a sample, and smelling the resultant
mixture. Explain the chemistry behind this test using words and a chemical reaction.
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Chem 212
Survey of Organic and Biochemistry
Spring 2007
11. (10 pts) Give the products of the following reactions:
CH3
OH
O
CH3
HCl (one equiv.)
N
N
CH3
CH3
O
H
O
H3 C
H2, Pt (excess)
+
CH 3CH 2OH, H
CH3
O
OH
HO
O
+
NaBH 4
H
CH3
O
CH3
K2Cr 2O 7
+
O H2, Pt (two equiv.)
O
OH
NH2
CH3
H3C
OH
CH3
O
O
12. (4 pts) Draw the structure of a substance that has the formula C6H12O which gives a
negative Tollen’s test, a positive iodoform test, and a positive 2,4-DNP test, and explain
what each test tells you about the structure. (There may be several correct structures)
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Chem 212
Survey of Organic and Biochemistry
13. (8 pts) Give the products of the following reactions:
O
CH 3OH, H
+
OH
+
NaHCO 3
H3N
N
O
H3C
(enol formation)
H3C
O
+
Ag (Tollen's reagent)
HO
14. (6 pts) Draw the structure of each of the following substances:
a. N,N-Dimethyl-3-aminooctan-2-one d. Triethylamine
b. 2,4-pentanedione
e. Cyclohexyl pentanoate
c. Butanedial
f. Potassium decanoate
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Spring 2007
Chem 212
Survey of Organic and Biochemistry
Spring 2007
15. (4 pts) Below each structure, draw the ketone form of each of the following enols. If no
ketone exits, write “no ketone”
OH
OH
HO
HO
HO
16. (6 pts) The following chiral ketone exists in equilibrium with an enol which is in equilibrium
with the enantiomer of the starting ketone. Draw these two structures.
O
(an enol)
(enantiomer)
17. (5 pts) The following table from Chemical & Engineering News shows the top 10 best selling
drugs of 2003 and indicates the form of the active ingredient(s). Based on this information, which
brand or brands of these drugs are candidates for the chiral switch strategy discussed in class?
What benefit is there to the pharmaceutical company to do a chiral switch? Explain your answer.
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Chem 212
Acid
HI
H2SO4
HBr
HCl
(CH3)2OH+
CH3OH2+
H 3O +
HNO3
H3PO4
HF
HCOOH
CH3CH(OH)COOH
CH3COOH
H2CO3
H2PO4H3BO3
NH4+
HCN
C6H5OH
HCO3HPO42H 2O
(CH3)3COH
HCCH
NH3
CH3CH3
Survey of Organic and Biochemistry
pKa
-10
-9
-9
-7
-2.9
-2.5
-1.74
-1.4
2.12
3.2
3.75
3.86
4.75
6.37
7.21
9.14
9.25
9.31
9.89
10.25
12.66
15.7
18
25
38
50
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Spring 2007