Organic Chemistry

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The two chaptersin Part Five deal with

aromaticity and the reactions of aromatic

compounds. Aromaticity was first intro-

duced in Chapter 7, where you saw that

benzene, a compound with an unusually

large resonance energy, is an aromatic

compound. We will now look at the crite-

ria that a compound must fulfill in order to

be classified as aromatic. Then we will ex-

amine the kinds of reactions that aromatic

compounds undergo. In Chapter 21, we

will return to aromatic compounds when

we look at the reactions of aromatic com-

pounds in which one of the ring atoms is

an atom other than a carbon.

In Chapter 15, we will examine the structural features
that cause a compound to be aromatic. We will also look
at the features that cause a compound to be antiaromatic.
Then we will take a look at the reactions that benzene un-
dergoes. You will see that although benzene, alkenes, and
dienes are all nucleophiles (because they all have car-
bon–carbon bonds), benzene’s aromaticity causes it to
undergo reactions that are quite different from the reac-
tions that alkenes and dienes undergo.

In Chapter 16, we will look at the reactions of substitut-
ed benzenes. First we will study reactions that change the
nature of the substituent on the benzene ring; and we will
see how the nature of the substituent affects both the re-
activity of the ring and the placement of any incoming
substituent. Then we will look at three types of reactions
that can be used to synthesize substituted benzenes other
than those discussed in Chapter 15—reactions of arene
diazonium salts, nucleophilic aromatic substitution reac-
tions, and reactions that involve benzyne intermediates.
You will then have the opportunity to design syntheses of
compounds that contain benzene rings.

p

Aromatic

Compounds

PART FIVE

Chapter 15

Aromaticity • Reactions of

Benzene

Chapter 16

Reactions of Substituted

Benzenes