Chemistry Reference
In-Depth Information
8.7
a.
Follow eq. 8.7 and then eq. 8.6 as guides.
2 L i
D
2
O
CH
3
CH
2
CH
2
Br
CH
3
CH
2
CH
2
Li
+
LiBr
CH
3
CH
2
CH
2
D
eth er
The resulting propane is labeled with one deuterium atom on one of the
terminal carbon atoms.
b.
Follow eq. 3.53, then eq. 8.6 as guides.
8.8
The reaction occurs by an S
N
2 mechanism. First a molecule of ethanol is protonated
by the acid catalyst:
H
+H
+
+
CH
3
CH
2
O
H
CH
3
CH
2
O
H
C
H
3
C
H
2
O
H
H
-H
+
O
+
CH
3
CH
2
O
CH
2
CH
3
CH
3
CH
2
CH
2
CH
3
+
H
2
O
Then a second molecule of ethanol displaces water, followed by loss of a proton to
regenerate the acid catalyst. The reaction does not go by an S
N
1 mechanism
because the ethyl cation, which would be an intermediate, is primary and not easily
formed.
8.9
Use eq. 8.8 as a model.
H
2
SO
4
2 CH
3
CH
2
CH
2
OH
(CH
3
CH
2
CH
2
)
2
O+ H
2
O
8.10
First the double bond is protonated to give a
t
-butyl cation, which then reacts with
methanol, a nucleophile, to give an oxonium ion. Loss of a proton gives
t
-butyl
methyl ether. Notice that the acid is a catalyst; it is needed for a reaction to occur,
but it is not consumed.
+H
+
H
2
C
C
(CH
3
)
2
(
CH
3
)
3
C+
H
+
CH
3
OH
H
-H
+
+
CH
3
O
C
(CH
3
)
3
CH
3
O
C
(CH
3
)
3
