PRACTICE FIRST HOUR EXAM B
ORGANIC CHEMISTRY 2220
1.
Which of the following pairs of compounds can be used as starting materials in the
synthesis of 2-phenyl-2-hexanol?
O
||
A. CH3 CH2 CH2 CH2 Br and
CCH3
O
||
B. (CH3 )2 CHCH 2 Br and
CCH3
O
||
C.
Br and CH3 CH2 CH2 CCH3
O
||
D.
Br and (CH3 )2 CHCH 2 CCH3
2.
Which of the following compounds will NOT react with Mg metal in the presence of ether
to give a Grignard reagent?
A. CH3 OCH 2 CH2 I
3.
B. CH3 CH2 CH2 I
C. CH2 =CHBr
D. HOCH2 CH2 Br
Which of the following sequences gives the highest yield in the reaction shown?
?
CH2 =CHCH 3 -----> CH2 CHCH 2 Cl
|
|
Br Br
A.
B.
C.
D.
4.
NBS in CCl4 ; then Cl2 in CCl4
Cl2 in CCl4 ; then NBS in CCl4
Br2 /CCl4 ; then Cl2 , light
Cl2 , light; then Br2 /CCl4
Which of the following compounds is the strongest base?
A. NaNH2
B. CH3 CH2 MgBr
C. NaOH
171
D. HC≡CMgBr
5.
Which of these compounds gives the SMALLEST number of signals in its proton nmr
spectrum?
A.
B.
OCH 3
6.
OCH 3
OCH 3
OCH 3
D.
C.
OCH 3
CH3 O
OCH 3
OCH 3
An unknown compound gave an IR spectrum containing a peak at 1715 cm-1 and a broad
peak between 2500 and 3000 cm-1 . Its proton nmr spectrum was:
triplet, δ1.3 (3H)
quartet, δ3.7 (2H).
singlet, δ4.1 (2H)
singlet, δ10.9 (1H).
What is the structure of this unknown?
7.
OCH 2 CH3
O
||
A. CH3 OCH 2 CH2 C–OH
O
||
B. CH3 OCH 2 C–CH2 OH
O
||
C. CH3 CH2 OCH 2 C–OH
O
||
D. CH3 CH2 C–CH3
What is the name of the compound shown?
CH3
A.
B.
C.
D.
1-methyl-1,4-cyclohexadiene
2-methyl-1,4-cyclohexadiene
1-methyl-1,3-cyclohexadiene
3-methyl-1,3-cyclohexadiene
172
8.
What is the major organic product of the reaction sequence shown?
CH3 Br
Br2 , light
[(CH3 )2 CH]2 CuLi ---------> -------------> ?
A.
B.
C.
D.
9.
10.
Which of the following carbocations is the MOST stable?
CH3
|
A. CH3 CH=CH–CH–CHCH3
CH3
|
B. CH3 CH=CH–CH2 –C–CH3
CH3
|
C. CH2 –CH=CH–CH2 CHCH 3
CH3
|
D. CH3 CH=CH–CH2 –CH–CH 2
What is the major organic product of the sequence of reactions shown?
A.
11.
(CH3 )2 CHCH 3
(CH3 )3 CBr
(CH3 )2 CHCH 2 Br
(CH 3 )2 CBrCH2 Br
O
||
C–OH
O
||
C–H
Mg
H 3O
H 2 CrO4
Br ------> ------------------> --------> -----------> ?
ether
O
O
OH
||
|
||
B.
D.
C
CH
C–H C.
Which of the following compounds is NOT a product of the reaction shown?
+ HCl ------> ?
A.
Cl
B.
C.
D.
Cl
Cl
173
Cl
12.
Which of the following compounds has the proton(s) having the HIGHEST chemical shift
(value of delta)?
A. CH4
13.
B. (CH3 )2 C=O
C. CH 3 Li
D. (CH3 )2 O
An unknown compound having the formula C4 H8 O gave the following proton magnetic
resonance spectrum:
multiplet, δ1.85 (4H)
triplet, δ3.75 (4H)
What is the structure of this unknown?
A.
14.
OH
O
D. CH2 =CH-CH 2 CH2 OH
Which of the following has the lowest energy per photon?
A. Ultraviolet
15.
B. CH3 CH=CH-CH2 OH C.
B. Microwaves
C. X-rays
D. Infrared
Which of the following is a valid resonance structure of the molecule shown?
:O:
| | ..
CH3 CH2 C—CH2
..
..
..
:O:
:O:
:OH
:O:
||
|
|
||
A. CH3 CH2 C—CH2 B. CH3 CH2 C=CH 2 C. CH3 CH2 C=CH D. CH3 CH2 C—CH
.. 2
..
16.
How many allylic hydrogen atoms are present in the molecule shown?
A. 2
B. 3
C. 4
D. 5
174
17.
Which of the following reaction sequences gives (CH3 )3 CCH2 CH2 CH3 as the major
organic product?
H2 , Ni Li
CuI (CH3 )3 CBr
A. CH3 CH=CH 2 ----------> ----> ------> ---------------> ?
H2 , Ni Li
CuI CH3 CH2 CH2 Br
B. (CH3 )2 C=CH 2 ----------> ----> ------> ---------------------> ?
Br2 , light Li
CuI CH3 CH2 CH2 Br
C. (CH3 )3 CH -------------> ----> ------> ---------------------> ?
Br2 , light Li
CuI (CH3 )3 CBr
D. CH 3 CH2 CH3 -------------> ----> ------> ----------------> ?
18.
Which of the following dienes has the SMALLEST heat of hydrogenation?
CH3
CH3
|
|
A. CH2 =CH–CH–CH2 CH=CH 2
B. CH2 =C=C–CH 2 CH2 CH3
CH3
|
D. CH2 =CH–C=CH–CH2 CH3
CH3
|
C. CH2 =CH–CH–CH=CHCH3
19.
What is the major organic product of the reaction shown?
O
||
H–C
20.
O
LiAlH4
H3 O
||
C–OCH 3 ----------> ---------> ?
A. HOCH 2
CH2 OH
O
||
B. H–C
C.
O
||
C–OCH 3
O
||
D. H–C
HOCH 2
CH2 OH
OH
|
CHOCH 3
What is the major organic product of the reaction shown?
H2 CrO4
CH3 CH2 CH2 OH -----------> ?
O
O
||
||
A. CH3 CH2 CH2 C–H B. CH3 CH2 C–H
175
O
O
||
||
C. CH3 CH2 CH2 COH D. CH3 CH2 COH
21.
How many signals are there in the proton nmr spectrum of the following compound?
Br
CH3 CH2
A. 4
22.
OCH2 CH3
B. 5
D. 7
Which of these compounds gives a singlet in its proton nmr spectrum?
A.
23.
C. 6
B.
C.
What is the major organic product of the reaction sequence shown?
O
||
C-CH3 +
A.
24.
D.
OH
|
CH
B.
H3 O
----------> ---------> ?
MgBr
O
||
C
C.
OH
|
C
|
CH3
What is the major organic product of the reaction shown?
+
A.
B.
---------> ?
C.
176
D.
D.
OH
|
C-CH3
|
CH3