Mcat Aromatics

Front 1

Define aromatic

Back 1

any unusually stable ring system

Front 2

Aromatic compounds are cyclic....

Back 2

conjugated, possess 4n+2 electrons, planar

Front 3

Why do aromatic compounds adopt planar conformation?

Back 3

to allow maximum overlap of their conjugated pi orbitals

Front 4

t or f
neutral compounds, anions, and cations all may be aromatic

Back 4

t

Front 5

aliphatic (define)

Back 5

any compound that is not aromatic

Front 6

Define antiaromatic

Back 6

Cyclic, conjugated polyenes that are destabilized

Front 7

Aromatic compounds can also be referred to as..

Back 7

aryl or arenes

Front 8

When named as a subsituent benzene is represented by..

Back 8

Ph

Front 9

Aliphatic compounds are called ____ and are represented by __.

Back 9

Aliphatic compounds are called alkyl and represented by the symbol R

Front 10

1,2 disubstituted compound is called?

Back 10

ortho

Front 11

1,3 disubstituted compounds are called

Back 11

meta-

Front 12

1,4 disubstituted compounds are called

Back 12

para-

Front 13

Name 4 polycyclic (multiple connected) or heterocyclic rings.

Back 13

napthalene
anthracene
pyrimidine
pyrrole

Front 14

Pyridines ____ can function as a ____ and pull a ____ out of solution

Back 14

lone pair, base, proton

**Pyrroles lone pair cannot

Front 15

t or f
pyrroles lone pair will react

Back 15

f

Front 16

The characteristic planar shape of benzene permits the rings six pi orbitals to

Back 16

overlap, delocalizing the electron density

Front 17

All 6 carbon atoms are ___ hybridized

Back 17

sp2

Front 18

Delocalization stabilizes the molecule, making it

Back 18

fairly unreactive

Front 19

Benzene doesnt undergo ___ reactions, but it will undergo ___ reactions

Back 19

addition, substitution

Front 20

With benzene, a substitution reaction means...

Back 20

a hydrogen atom on the ring is replaced by another group

Front 21

Most common examples to EAS are:

Back 21

halogenation, sulfonation, nitration, aklylation, and acylation

Front 22

Aromatic rings react with ___ in the presence of a ___ to yield ____.

Back 22

Br or Cl, lewis acid, monosub. products

Front 23

Why are halogenation reactions with F and I less useful?

Back 23

F- highly reactive, produce multisubstituted products
I- lacks reactivity, requires special conditions

Front 24

In sulfonation what do the aromatic rings react with?

Back 24

Sulfuric acid, sulfur trioxide, and head

Front 25

Product of sulfonation?

Back 25

Sulfonic acids

Front 26

Is sulfonation reversible?

Back 26

yes

Front 27

What is a nitronium ion?

Back 27

NO2+ (strong electrophile)

Front 28

How do you produce nitro compounds?

Back 28

Nitronium with aromatic ring

Front 29

For nitration the product of this reaction is the ____ reactive substituted compound b/c it is ____ reactive

Back 29

least, least

Front 30

Describe Friedel-Crafts acylation

Back 30

An acyl group is turned into a carbocation by a Lewis acid, the carbocation acyl group is then incorporated into aromatic ring

Front 31

Substitution groups are groups according to whether they ____ or ____ substitution

Back 31

enhance or inhibit

Front 32

Define activators

Back 32

groups that donate electron density

Front 33

Define deactivators

Back 33

groups that withdraw electron density

Front 34

Activators direct new substituents to

Back 34

o/p positions

Front 35

Deactivators direct new substituents to

Back 35

meta positions

Front 36

Halogens are ____ and direct to the ___ position

Back 36

mild deactivators, o/p position

Front 37

Benzene rings can be reduced to ____ by ____.

Back 37

cyclohexane, catalytic hydrogenation

Front 38

Benzene reduction catalysts include:

Back 38

Ruthenium or rhodium
Platinum or palladium (higher pressure required)

**elevated temp. and pressure

Front 39

Aromatic compounds are particularly _____.

Back 39

Stable