Chapter 18- Reaction of Aromatics (Part 3- After Exam 2)

Question 1

What is the inducive effect?

Answer 1

substituents donate/withdraw electron density through s-bonds to/from aromatic ring

-I = withdraw
+I = Donate
Same goes with resonance (+R/-R)

Question 2

What are the three classifications of substituents?

Answer 2

1) Ortho, Para directing Activators
2) Meta directing Deactivators
3) Ortho, Para directing Deactivators

Question 3

What are some Meta Directing Deactivators?

Answer 3

NO2
NR3
CN
O=CR
SO3H
CO2H
CHO
O=COR

Question 4

What are some Ortho-Para directing Deactivators?

Answer 4

Br
F
I
Cl

Question 5

What are some Ortho-Para directing Activators?

Answer 5

R
Ar
OR
NH3
NHCOCH3
OH

Question 6

What is the major product and why?

Answer 6

o-nitrotoluene (60%)
The methyl group is an activator

Question 7

What type of additions are favored and why?

Answer 7

Ortho and para additions are favored/preferred because their
resonance structures include
tertiary carbocation.

Question 8

What position on a ring is the major product when a methoxy group is on the reactant?

Answer 8

The methoxy group donates electron density via resonance (so stronger activator
than alkyl)

para is the major, due to the ortho positions being more sterically hindered

Question 9

What is a methoxy group classified as?

Answer 9

Activating through resonance

Question 10

What is a Nitro group classified as?

Answer 10

A deactivating group

Question 11

In a reaction, what position on the ring is the major product when a nitro group is involved?

Answer 11

Meta

Question 12

What position on a ring is favored when addition is being done on a ring with a halogen substituent?

Answer 12

Ortho and Para (through resonance)

Question 13

When proposing a synthesis, what is the order that should be kept in mind?

Answer 13

When proposing a synthesis, typically introduce activators (strong then weak) first,
then deactivators (weak then strong) to the aryl ring.

Question 14

If the directing effects of two substituents reinforce each other, what happens?

Answer 14

If the directing effects of two substituents reinforce each other, the predicted
product predominates

Question 15

If the directing effects of two substituents oppose each other, what happens?

Answer 15

If the directing effects of two substituents oppose each other, the more
activating group dominates, but mixtures often result.

Question 16

Does substitution occur between two substituents that are meta to each other?

Answer 16

No, too crowded

Question 17

What happens when there is a bulky o,p- director and/or a bulky electrophile?

Answer 17

para substitution
predominates

Question 18

What product dominates in an monosubstituted ring?

Answer 18

Para

Question 19

Where will substitution occur on a 1,4 disubstituted ring?

Answer 19

Less sterically hindered site

Question 20

Where does substitution not occur on a 1,3 disubstituted ring?

Answer 20

Between the existing substituents