CH 243 ORGANIC CHEMISTRY 1 (FALL 2008) - EXAMINATION 1
(September 18,2008)
Name:
Recitation Section:
(Please print)
Pledge: I pledge my Honor that I have abided by the Stevens Honor System.
Answer the following questions. Please indicate the letter/ number choice of your answer clearly. All
multiple choice problems are worth 4 points, short answers are worth 3 points.
The following scheme represents a series of reactions of ethanol: Ethanol (I) reacts with potassium
permanganate (II) in acidic solution and is converted, sequentially to ethanal (III) and ethanoic acid (IV). In
this reaction.
O-l
rt
|| w
+1 n ^ + V2 ^v*-' 2 ^ 1
-»* H3C—C—OH
KMn04, H + CH3CH2OH
H 3 C—C—H
O
-2
-\
-\
1. Identify the species oxidized:
VO , - H
2. Identify the reducing agent:
Identify the more stable stereoisomer in each of the following pairs:
3. l-(l-methylethyl)-2-methylcyclohexane: (a) cis (b) trans
S—N
""
4. l-(l-methylethyl)-3-methylcyclohexane: (a) cis (b) trans
5. l-(l-methylethyl)-4-methylcyclohexane: (a) cis (b) trans
(a)
6.
CH3
(b)
CH3
CH
(a)
7.
r—^1
H3C
CH3
fo
Identify the compound with the higher enthalpy (heat) of combustion:
iess
8. Isomers of molecular formula C6H|4: (a) hexane (b) 2,3-dimethylbutane
9. Isomers of 1,2-dimethylcyclopropane: (a) cis
10. (a) Undecane
(b) Dodecane
(b) trans
11. Ihe fungus Pseodomonas oleovorans oxidizes the CHj groups at the end of a carbon chain faster than a
CH3 branch and internal CH2 and CH. Assuming this selectivity, which of the following is expected to give
Constitutionally isomeric alcohols upon oxidation?
A. heptane)
^EL 3-methylheptane
C. 4-methylheptane
D. 4,4-dimethylheptane
_-C-C -C
*C-c- C-c-c-c-c-
-c-c-c-c-c-c-c-
C
-c-c-c-c-c-c-c-
C-
<-
Female German cockroaches convert the alkane shown below to a substance that attracts males.
CH 3 CH^CH(CH,) 7 CH(CH,)i 6 CH,CH 3
"iCH
'
3
CH 5
C.
c ( OG - <CH^O - <; - co^.s, - c - c -
-^^±J^.
-C-
H'
12. Oxidation at the C-2 of the alkane gives the sex attractant, which has a molecular formula C3iH62O and
the same carbon skeleton as the alkane. Which of the following is the structure of the sex attractant?
(A)
OH
I
CH3CH.CH(CH,)7CH(CH2)16CHCH3
I
CH-,
CH3
13CHCH(CH,)
7 CH(CH 2 ) 16 CH 2 CH 3
t:
3
I "
CH 3 ,
^
I
CH 3
-C- C-c
O
CH3CCH(CH^)7CH(CH2)16CH2CH3
CH3CH2CH(CH2)7CH(CH2)i6CCH3
CH3
CH3
-c-c-C
-n
Biological oxidation of the hydrocarbon adamantane by the fungus Absidia glauca gives a mixture of two
alcohols. Answer questions 13-15.
OH
major product
^
.—-"
Adamantane
minor product
13. Classify the carbon in adamantane that is oxidized in forming the major product.
A. primary
B. secondary
(^C tertiary^)
D. quarternary
14. What type of ringsy^gfem isjgpresented in adamantane?
A. monocyclic
(^BTbicyclicX
^,tricyclic
D. tetracyclic
JL5. What type of ring system is represented in adamantane?
CjB.brI3gT>
C. spirocyclic
^fused -^
D. heterocyclic
~^—
—^^
^^.
Ij&^Tridecane is the major component of the repellant which the stink bug Piezodorus guildinii releases
/from its scent glands when attacked. What fatty acid gives tridecane upon decarboxylation?
B.CH3(CH2)nCOOH
D. CH3(CH2)i3COOH
17. What are the hybridizations of carbon atoms 2, 3, and 4 shown below?
I
V
-c- CE c- c- cA. sp, sp2, sp2
B. sp, sp2, sp3
C. sp, sp, sp
18. Arrange the following compounds in order of decreasing oxidation state
c - c- C
1
1°
OH
O-H
A. 1 > 2 > 3
D. 2 > 1 > 3
F73>2>1
O - \A
,9. The most stable chair conformation of c/5-l-/e/-/-butyl-3-methylcyclohexane has
^Ayboth groups equatorial.
C the /erf-butyl group equatorial and the methyl group axial
i. both groups axial.
Tlhe /w/-buiyl group axial arid Ihe iffelhyl gi*oup equat
juatorial.
20. The most stable conformation of the compound shown has
A. all methyl groups equatorial.
B. equatorial methyl groups at C-l and C-2, axial at C-4.
C. equatorial methyl groups at C-l and C-4, axial
IJTequatonal methyl groups at C-2 and C-4, axial a
Indicate the number of primary, secondary, tertiary and quaternary carbons in the following alkane:
Cx
C-C-c-c - c-c
21. Primary carbons
QHQCVTPd -KJ
*
22. Secondary carbons
i
23. Tertiary carbons
s
24. Quaternary carbons
i ne amiae Functional group is an important structural unit in peptides and proteins. Formamide (molecular
formula CH3NO), represented by the Lewis structures below, is the simplest amide with a net dipole
moment 01*3.7 D. Xnswer the following questions (1-6) with respect to the Lewis structures shown.
,H
H
^C^..^H
I
^C^..^,H
i
H
II
i
H
1
/c^.
HI
r
H
^0*
IV
r
H'
.C^^H
V
H
H
CUiN C
25. The most appropriate structure for formamide is:
26. Which Lewis formula is a resonance contributor to the structure of formamide?
27. Which Lewis formula is a constitutional isomer of formamide?
28. Which Lewis formula corresponds to the cmyugaj^jcjsi.of formamide?
29. Which Lewis formula corresponds to the conjugate base of formamide?
30. According to VSEPR, which Lewis formula has a trigonal pyramidal arrangement of bonds to nitpogen?
•o:
r
-C-M--U
sp7-
-
T
j,
Bonus Problem: (10 points) A typical steroid skeleton is shown below. Specify in each case whether the
designated substituent is axial (A) or equatorial (E). (All questions must be answered correctly to receive
credit)
CH3
(a) Substituent at C-l cis to the methyl group.
(b) Substituent at C-4 cis to the methyl group.
(c) Substituent at C-7 trans to the methyl group.
(d) Substituent at C-l 1 trans to the methyl group.
(e) Substituent at C-l2 cis to the methyl group.
Periodic Table of the Elements
Noble
gases
8A
2
He
IA
1
2
3
Q
0 4
2U4
Q.
5
6
7
1
H
l.tttt
Hydrugen
2A
3
Li
4.0(13
Helium
8
0
7A
9
F
14.01
Nitrogen
16
Oxygen
19.00
Fluorine
20.18
Neon
14
Si
15
P
16
S
17
Cl
18
Ar
26.98
Aluminum
28.09
Silicon
30.97
Phosphorus
3207
Sulfur
39.95
Argon
31
Ga
32
Ge
34
Se
35.45
Chlorine
35
Br
Kr
78.96
Selenium
79.90
Bromine
83.80
Krypton
5A
7
N
! lilt inn
9.012
4A
6
C
6A
4
Be
3A
5
B
Beiyllium
10.81
Boron
12.01
Carbon
11
Na
12
Mg
13
Al
22.99
Sodum
24.31
Magnesium
19
K
6.941
4B
22
Ti
5B
20
Ca
3B
21
Sc
39.10
Potassium
40.08
Calcium
4496
Scandium
47.867
Titanium
50.94
Vanadium
3?
Rb
38
Sr
39
Y
40
Zr
41
Nb
85.47
Kuhiilium
87.62
Strontium
88.91
Yttrium
91.22
Zirconium
92.90
Niobium
56
Ba
71
Lu
72
Hf
55
Cs
1319
23
V
73
Ta
6B
24
Cr
7B
25
Mil
r26
Fe
— 8B27
Co
—,
28
Ni
IB
29
Cu
2B
30
Zn
55.85
(run
5H.93
Cobalt
58.70
Nickel
63.546
Copper
65.39
Zinc
69.72
Gallium
72.64
Germanium
33
As
74.92
Aitcuic
43
Tc
44
Ru
45
Rh
46
Pd
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
54
Xe
95.94
(98)
101.07
47
Ag
102.9
Rhodium
106.4
Palladium
107.9
Silver
112.4
Cadmium
114.8
Indium
121.8
Antimony
127.6
Tellurium
126.9
Iodine
131.3
Xenon
74
W
75
Re
77
lr
78
Pt
79
All
197.0
80
Hg
81
Tl
118.7
Tin
82
tiold
200.6
Meicurv
204.4
Thallium
54.94
52.00
Chiomium Manganese
42
Mo
Mulytnluiuni Tcchnciiimi Ruthenium
76
Os
Cesium
137.327
Barium
175.0
Lutetiunl
178.5
Hafnium
180.9479
Tantalum
183.84
Tungsten
186.2
Rhenium
190.23
Osmium
192.2
Indium
195.1
Platinum
8?
Ft
88
Ra
103
Lr
104
Rf
105
Db
107
Bh
108
Us
109
Mt
110
111
112
(223)
Frunduni
(226)
Radium
(257)
Lawrencium
(261)
106
Sg
(262)
Dubnium
(263)
ScHDoigium
(262)
Bohrium
(265)
Hassium
(266)
Meitncnum
(269)
(272)
(277)
RulhfiiiMiliiini
57
*La
58
Ce
59
Pr
63
Eu
64
Gd
65
Tb
138.9
Lanthanum
140.1
Cerium
Plast. utKiniuin
89
'Ac
90
Th
91
Pa
92
U
93
Np
(227)
Actinium
232.0
Thorium
(231)
Protactinium
238.0
Uranium
(237)
Neptunium
Lanlhanide series:
* Actinide series:
10
Ne
140.9
60
61
62
I'll.
Sm
(145)
144.2
150.4
NeoJjmium Promcthium Samarium
Nd
94
Pu
152.0
157.3
hurupium Gadolinium
95
Am
(244)
(243)
Plutonium Amenaum
96
Cm
(247)
Curium
Pb
207.2
Lead
114
fe
83
Bi
84
Po
85
At
209.0
Bismuth
(209)
Polonium
(210)
Astatine
L
116
k
66
67
Ho
68
Er
69
Tin
158.9
Terbium
D\pro!»ium
164.9
Holmium
167.3
Erbium
168.9
Thulium
97
Bk
98
Cf
99
Es
100
Km
101
Mil
(247)
(251)
(252)
Berkcliunt Californium Einsteinium
. .
*Numbers in parentheses are mass numbers of the most stable or best-known isotope of radioactive elements.
86
Rn
(222)
Radon
. •.•»'<«[*
(289)
(285)
Dy
1A2.5
36
(257)
Fcrmium
70
Yb
173.0
Ytterbium 1
102
No
(259)
(258.10)
Mi/udeicvium Nohcllium 1
.
i , ™