HOUSTON COMMUNITY COLLEGE
SYSTEM
Sample Final Examination
2423 Organic Chemistry I
Name:_________________________________
Part 1. Multiple choice questions (2 points each): Please bubble your correct answer
in the scantron
1. Which of the following molecule(s) contain(s) an sp3-hybrized N-atom?
N
1. N(CH3)3
A. 1 &4
2. NH4+
B. 2
3.
C. 3
4. HCN
H
D. 1, 2 & 3
2. What is the formal charge on the nitrogen atom in the following molecule?
N
B. –1
A. +1
C. 0
D. +2
3. What is the IUPAC name of the following molecule?
C(CH3)3
CH3(CH2)2C(CH3)(CH2)2CH3
A.
4- butyl-4-methyl heptane
C. neodecane
B. 4-(1,1-dimethyl)ethyl-4-methyl heptane
D. 4-isopropyl-4-methylheptane
4. Which one of the following dimethylcyclohexanes is most stable?
H
H
H
CH3
H
H
H
H
H
H3C
H3C
H
H
H
H3C
H
H
CH3
H
H
H
CH3
H
H
H
H
H
3
2
A. 1
B. 2
C. 3
D. 1 & 3
5. Observe structures 1 and 2 in question 4 and choose right statement (s).
1
A. Structure 1 suffers from two 1,3-diaxial interactions
B. Structure 2 suffers from four 1,3-diaxial interactions
C. Structure 1 suffers from four 1,3-diaxial interactions
D. Structures 1 & 2 both suffer from two 1,3-diaxial interactions
6. Isopentane and neopentane are
A. Sterio isomers
C. cis and trans isomers
B. constitutional isomers
D. optical isomers
7. Which one of the following molecules has resonance structures?
A. CO
B. CO2
C. O2
D. O3
8. How many degree of unsaturations are in C6H9N2OCl
A. 10
B. 5
C. 3
D. 7
9. What is the major product of the following reaction?
H2SO4 /heat
CH2OH
A.
D.
C.
B.
CH3
H
H
H
H
H
H
H
H
CH2
CH3
H
10. How many allylic hydrogens does the following compound has?
CHCH2CH3
A. 8
B. 4
C. 10
D. 5
11. The following compounds have same molecular formula. Which two are tautomers?
CH3-CO-CH2CH3
CH3-O-CH2CH=CH2
CH3CH2CH2CHO
2
3
1
A. 1 and 2
B. 1 and 3
CH2=C(OH)CH2CH3
4
C. 1 and 4
D. 3 and 4
12. What is the product in the following reaction
CH3CH=CHCH3
A. CH3CHO
O3
Zn, H3O+
B. CH3COCH3
C. CH3COOH
D. CH3CH2COOCH3
13. Which of the following products would be the result of the following reaction?
1. BH3, THF
CH3-CH2-CH2-C CH
2. H2O2, NaOH, H2O
A. CH3 – CH2 – CH2 – CH2-CH3
C. CH3 – CH2 – CH2 – CH2 – COOH
B. CH3 – CH2 – CH2 – CH2 – CHO
D. CH3 – CH2 – CH2 – CH2 – COCH3
14. What is the reagent in the following reaction?
Cl
A. CH2Cl2 & KOH
B.
Cl
& HCl
C.
Cl
D.
15. Which of the following alkenes is most stable?
B.
A.
D.
C.
16. What is the product in the following reaction?
+ CH2I2
Zn(Cu)
Ether
A.
CH3
B.
C.
17. Vinylic carbocation intermediate is observed in
A. Hydrohalogenation of alkene
B. Halogination of Alkane
C. Hydrohalogination of Alkyne
D. Hydrogenation of Alkene
D.
18.
NaNH2, NH3
CH3C CH
CH3C C
R
In the above reaction ‘R’ is
A. Methylcyclopropane B. Bromocyclopropane C. Cyclopropene
D. Cyclopropanol
19. In what type of reactions formation of carbocation is a rate determining step?
I. SN1
II. SN2
III. E1
IV. E2
A. I, II
B. II, IV
C. III, IV
D. I, III
20. Which one of the following free radicals is most stable
R
R
R
C
R
C
R
C
R
A. I
H
R
I
H
H
III
II
B. II
C
C
C
R
H
H
C
C. III
CH3
IV
D. IV
21. What is the relationship between these two compounds?
H
H3C
H
Br
Br
CH3
H3C
Br
and
CH3
Br
H
A. identical
B. Constitutional isomers
H
C. diastereoisomers
D. enantiomers
22. Identify the alkyl halide in the following reaction
CH2
Alkylhalide + KOH
+ KBr + H2O
A. Bromethyl cyclohexane
B. 1-bromo-1-methyl cyclohexane
C. 1-bromo-2-methyl cyclohexane
D. A & B
23. Which of the following can not be detected by IR SPECTRUM?
A. C-C stretching
B. C=O vibration
C. C-C bond length D. C-H bond stretching
24. Which one of the following process leads to recemic mixture
A. SN1
B. SN2
C. E1
D. E2
25. Predict the major product in the following reaction
H
H
H
E2 elimination
or
I
II
Cl
A. I
B. II
C. I & II 50%
H
D. None
Part II. Nomenclature and Structures (2 points each)
a) Give the IUPAC name of the following compounds (E & Z notations if necessary)
CH3
Cl
H
I
II
I. _______________________________________
II. _______________________________________
III. ______________________________________
b. Draw structures corresponding to the following systematic names
1. (2S,3R)-2,3-dibromo-2-hydroxybutane
2. (1Z, 3E) 1,2-dichloro-1,3-pentadiene
Part III. Reactions (2-points each)
Give the major product(s) of each of the following reactions. Show all relevant
stereochemistry.
Br
1.
KOH/ ethanol
1) BH3, THF
2.
2) H2O2 , OH
KMnO4
3.
4.
5.
H3O
CH2I2 / Zn(Cu)
1) O3
2) Zn / H3O
C
6.
C- H
2HBr
CH3
7.
NBS/hv
C
Cl
E1 elimination
8.
H
Cl
H
9.
CH3 - CH2 - CH - CH2Br
CH3
1) 2 Li, pentane
2) CuI
3) CH3-CHBr
CH3
10.
CH3CH2CHBrCH(CH3)2
KOH
Ethanol
Part IV. Multi step synthesis (3 points each): Show by a series of reactions how you
can prepare the following compounds (manor) from the starting compounds. Be sure to
indicate the reagent used in each step.
1.
2.
CH3
CH3
C
H3C
C
C
Br
H
H3C
C
H3C
C
C3H7
3.
O
Part V. Mechanisms (3 points each): Write complete mechanisms for the following
reactions. Show all intermediates, rearrangements, and electron flow using the curved
arrow convention
1.
OH
Br2/H2O
Br
2.
OH
H2SO4
Part IV. Spectra: (5 points)
Given the MS spectrum for a substituted (cyclo) alkane having formula C6H12, answer
the following questions
41
a) Determine the position of parent peak and base peak.
b) Determine the possible structure of the compound.
c) What is the structure of the fragment that shows mass of 41?
Answer Key
Part 1. Multiple choice
1-D; 2-C; 3-B; 4-C; 5-C; 6-B; 7-D; 8-C; 9-C; 10-D; 11-C; 12-A; 13-B; 14-A; 15-C; 16-B;
17-C; 18-B; 19-D; 20-B; 21-D; 22-A; 23-C; 24-A; 25-B
Part II. Nomenclature and structures
I.
II.
III.
6-chloro-1-methylcyclohexene
(2Z, 4E) 3,5-dimethyl-2,4-heptadiene
3-ethyl-hex-2-ene-4-yne
1.
2.
Br
H
CH3
H
OH
CH3
Br
H
C
C
Cl
CH3
C
C
H
Cl
Part III. Reactions
O
OH
2
O
1
O
2
O
5
4
3
Br
Br
Br
Br
and
Cl
6
Cl
7
10
8
9
Part IV. Multi step synthesis
1.
Br
Cl2
KOH
hv
EtOH
Cl
NBS
hv
KOH
EtOH
2.
CH3
C
2LI
C
H3C
CH3
Br
C
H3C
CH3
C
+ LiBr
C
Li
CuI
CH3
CuLi + LiI
C
C
Ether
H3C
Li
C
H3C
2
Gilman reagent
I
0C
CuLi
C
+
C
C
C3H7
H3C
H3C
CH3
H
CH3
H3C
2
C
H3C
3.
rapid
H2O, H2SO4
HgSO4
OH
enol
O
Ket
o
CH3
H
Ether
+
C
C3H7
C
H3C
+ LiI
C
Cu
Part V. Mechanisms
1.
Br
Methanide shift
Br
Br
Br
OH2
OH
H3O+
Br
Br
+
O
H2O
H
H
2.
H
-H2O
OH
H
HSO4
O
H
Methanide shift
-H2SO4
H
HSO4
Part VI. Spectra.
a. 84 and 69
b.
c.