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Chapter 18 629
Copyright © 2017 Pearson Education, Inc.
69.
meta
-Xylene reacts more rapidly. In
meta
-xylene, both methyl groups activate the same position, whereas in
para
-xylene, each methyl group activates a different position. Therefore,
meta
-xylene is more highly activated.
CH
3
CH
3
CH
3
CH
3
70.
The reactions in part
a
and part
b
are intramolecular Friedel–Crafts acylation reactions.
a.
Drawing the mechanism can help you determine the product of the reaction.
Cl
AlCl
3
Cl AlCl
3
−
HB
+
AlCl
4
−
+
B
O
+
H
O
O
O
O
b.
The mechanism in part
a
can help you determine the product.
O
c.
CH
2
71.
The
1
H NMR spectrum is the spectrum of butylbenzene.
The benzene ring protons at 7.2 ppm that integrate to 5 protons indicate a monosubstitutied benzene ring.
The two triplets and two multiplets indicate a straight-chain butyl group.
CH
2
CH
2
CH
2
CH
3
Therefore, the acyl chloride has a straight-chain propyl group and a carbonyl group that will be reduced to
a methylene group.
CH
3
CH
2
CH
2
O
Cl
C