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Chapter 18 603
Copyright © 2017 Pearson Education, Inc.
17.
a.
CH
2
CH
2
CH
3
NO
2
CH
2
CH
2
CH
3
NO
2
+
b.
Br
NO
2
+
Br
NO
2
c.
NO
2
C
O
H
d.
NO
2
C
N
e.
NO
2
SO
3
H
f.
NO
2
+
NO
2
18.
They are all meta directors:
a.
This group withdraws electrons by resonance from the ring. The relatively electronegative nitrogen
atom causes it to also withdraw electrons inductively from the ring.
CH CH C N
b.
NO
2
withdraws electrons inductively and withdraws electrons by resonance from the ring.
c.
CH
2
OH withdraws electrons inductively from the ring.
d.
COOH withdraws electrons inductively and withdraws electrons by resonance from the ring.
C OH
O
e.
CF
3
withdraws electrons inductively from the ring.
f.
N
“
O withdraws electrons inductively and withdraws electrons by resonance from the ring.
You can draw resonance contributors for electron donation into the ring by resonance. However, the
most stable resonance contributors are obtained by electron flow out of the benzene ring toward oxygen
because oxygen is the most electronegative atom in the compound.
N O
N O
19.
Solved in the text.
resonance electron donation
into the ring
resonance electron withdrawal
out of the ring