Chem 220
Mid-Term Exam II
March 18, 2004
V.2
Name:
Answer Key
Student ID:
There are 5 sections to this exam, each section indicates how the
questions are to be answered.
Answer ALL questions in Parts I to IV
Answer 1 of 2 questions in Part V
Please make sure your exam paper is complete.
Do not start writing exam until indicated.
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Part I. (2 pts each).
Name or draw the following compounds according to IUPAC nomenclature, using all
appropriate notations. Indicate stereochemistry where necessary
Structure
Name
O
CH3
OH
1.
4-Methylpentanoic acid
CH3
2.
2.
1-Cyclopentenecarbonyl chloride
O
3.
cyclopentylpropyl ether
4.
3-tert-Butyl 6-methyloctanenitrile
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Structure
Name
O
5.
Hexanamide
NH2
6.
2.
3-Methyl-3-butenal
O
7.
CH2
CH3
Ethyl acetate
C
O
CH3
8.
Propionic anhydride
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Part II (3 pts each)
Fill in the blank with the appropriate answer (#’s 9-13)
9. Fisher Esterfication is the reaction of a carboxylic acid plus a(n)
alcohol
under acid catalyst in an alcohol solvent to produce an ester.
10. A cyclic ether where the two C bonded to the oxygen are also bonded to each other is also
known as a(n)
epoxide
11. Define acetal.
functional group consisting of two ether type-oxygen atoms bonded to the same
carbon [R2C(OR')2]
12. The net result of malonic ester synthesis is to lengthen a primary alkyl halide by
2 Carbons
.
O
13. The
C
functional group is called a(n)
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carbonyl group
.
Part III. (#'s 14-25) (3 pts each)
Write the letter of the most appropriate answer for the following questions in the blanks provided
14. Which of the following carboxylic acid derivatives is the most reactive?
A. amide
B. ester
C. acid chloride
D. acid anhydride
14.
15. Claisen condensation
A. Takes place by a very different mechanism than the aldol
reaction.
B. Does not have a leaving group as part of the reaction.
C. Occurs between aldehydes.
D. Occurs between esters with an -hydrogen.
15.
D
16. Which of the following is TRUE of conjugate (1,4) addition to a C – C
16.
double bond?
A. The nucleophile adds to the aldehyde or ketone O.
B. The reactant is an  unsaturated aldehyde or ketone.
C. The nucleophile adds to the aldehyde or ketone C.
D. The electronegative oxygen of the aldehyde or
ketone donates electrons to the -carbon.
B
17. Which of the following is NOT true of enols?
A. Enols behave as electrophiles
B. Enol formation is base-catalyzed because the presence of the
C=O makes the a-C hydrogens more acidic.
C. Enol formation is acid-catalyzed by protonation of the C=O
oxygen group.
D. Enols are tautomers of their corresponding keto form.
17.
A
18.
18.
D
Which of the following reactants would yield a 1o alcohol upon reaction
with LiAlH4?
A. Cyclopentanone
B. 2-Pentanone
C. Pentyne
D. Pentanal
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C
Part IV (3 pts each)
Write the products of the following reactions (#’s 19-26). If no reaction, write NR. Give all
major products (if more than one) and indicate stereochemistry where necessary.
2 CH
O
CH3
3
O
1. NaOCH3
2.
CH3
H3O+
O
19.
O
O
CH3
O
1. Br2
CH3
Br
2. CH2COOH
20.
O
H3C OH
O CH3
O CH3
H+ catalyst
21.
O
1. CH3CH2MgBr, ether
HO
2. H3O+
22. .
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CH2 CH3
+
CH3OH
CH3
O
CH3
H Br
C CH3
CH3
+
OH
S Na
+
S
Cl
O
O
Na
O
+
O
O
Cl
25.
O
HC
C CH3
CH3
23.
24.
Br
N
N C
26.
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O
O
Part V. (10 pts)
Answer ONE of the two following questions in the space provided. For each, the point
breakdown is 2 pts reactant structure(s), 6 pts mechanism, 2 pts product name(s)
27. Draw the reaction mechanism for a nucleophilic addition reaction of
cyclopentanecarbaldehyde with water under acidic conditions and name the product(s).
28. Draw the reaction mechanism for the aldol condensation of 2 molecules of propanal under
basic conditions and name the product(s). (2 pts reactant structure, 6 pts mechanism, 2 pts
product name(s)).
27.
O
O
H
H
+
H OH
catalyst
+
OH
See book for mechanism
O
28.
+
O
O
OH
See book for mechanism
I
II
III
IV
V
Total
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