Organic Chemistry

620 CHAPTER 15 Aromaticity • Reactions of Benzene

27. Which ion in each of the following pairs is more stable?


28. Which can lose a proton more readily, a methyl group bonded to cyclohexane or a methyl group bonded to benzene?


29. How could you prepare the following compounds with benzene as one of the starting materials?


30. Benzene underwent a Friedel–Crafts acylation reaction followed by a Clemmensen reduction. The product gave the following
    spectrum. What acyl chloride was used in the Friedel–Crafts acylation reaction?


31. Give the products of the following reactions:


32. Which compound in each of the following pairs is a stronger base? Why?


33. a. In what direction is the dipole moment in fulvene? Explain.
    b. In what direction is the dipole moment in calicene? Explain.

calicene

CH 2

fulvene

N

or

NH 2

N

H

CH 3 CHCH 3

NH

a. b. or CH 3 CNH 2

1. AlCl 3
   2. H 2 O

CH 2 CH 2 CH 2 CCl

O

d.

1. AlCl 3
   2. H 2 O

CCH 2 CH 2 Cl

O

b.

1. AlCl 3
   2. H 2 O

CH 2 CH 2 CCl

O

CCH 2 CH 2 CH 2 Cl c.

O

a.

1. AlCl 3
   2. H 2 O

4

δ (ppm)

frequency

10 9 8765 3210

(^1) H NMR
C
a. b. O
d. or

• or
  −
  b.
  or


• −
  or c.


• −
  a.