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Chapter 8 265
Copyright © 2017 Pearson Education, Inc.
Dewar benzene is not in accordance with what early chemists knew about the structure of benzene, because
it would form two monosubstituted compounds and six disubstituted compounds and it would undergo
electrophilic addition reactions.
Br
Br
Br
Br
Br
Br
Br
Br
Br
Br
Br
Br
Br
Br
3.
a. 2, 4,
and
5
have delocalized electrons.
1, 3, 6,
and
7
do not have delocalized electrons, because electrons cannot be moved to an
sp
3
carbon.
2.
CH
3
CH
CH
2
CH CH CH
CH
3
CH
CH
2
CH CH CH
CH
3
CH
CH
2
CH CH CH
+
+
+
4.
N
H
N
H
+
−
N
H
+
−
N
H
+ −
N
H
+
−
5.
NH
2
+
NH
2
−
4.
a.
CH
3
CH
2
C CH
2
CH
2
+
CH
3
CH
2
C CH
Less stable, because the positive charge is shared by two primary allylic carbons.
2
CH
2
CH
3
CH
2
CH CH CH
2
CH
3
CH
2
CH CH CH
2
+
+
+
More stable, because the positive charge is shared by a primary allylic and a secondary allylic carbon.