tailieunhanh - Ebook Organic chemistry (4th edition): Part 2

(BQ) Part 2 book "Organic chemistry" has contents: Aromatic compounds; reactions of substituted benzenes, carbonyl compounds I; more about oxidation–reduction reactions; more about amines heterocyclic compounds, carbohydrates, catalysis,. and other contents. | BRUI15-593_621r3 27-03-2003 2:51 PM Page 593 FIVE 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 undergoes. You will see that although benzene, alkenes, and dienes are all nucleophiles (because they all have carbon–carbon p bonds), benzene’s aromaticity causes it to undergo reactions that are quite different from the reactions that alkenes and dienes undergo. Aromatic Compounds PA R T The two chapters in Part Five deal with aromaticity and the reactions of aromatic compounds. Aromaticity was first introduced 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 criteria that a compound must fulfill in order to be classified as aromatic. Then we will examine 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 compounds in which one of the ring atoms is an atom other than a carbon. Chapter 15 Aromaticity • Reactions of Benzene Chapter 16 Reactions of Substituted Benzenes In Chapter 16, we will look at the reactions of substituted 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 reactivity 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 reactions, and reactions that involve benzyne intermediates. You will then have the opportunity to design syntheses of compounds that contain benzene rings. 593 BRUI15-593_621r3 27-03-2003 2:51 PM Page 594 15 Aromaticity • .