chapter 17 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Chapter 17 PowerPoint Presentation
Download Presentation
Chapter 17

Loading in 2 Seconds...

play fullscreen
1 / 54

Chapter 17 - PowerPoint PPT Presentation


  • 279 Views
  • Uploaded on

Chapter 17. Alcohol & Phenol ROH & ArOH. Chapter 17. Naming Properties Synthesis Reactions. 5-methyl-2,4-hexanediol. 2-methyl-4-phenyl-2-butanol. 4,4-Dimethylcyclohexanol. trans -2-Bromocyclopentanol. 4-Bromo-3-methyl-phenol. ( o = ortho(1,2), m = meta(1,3), p = para(1,4)).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Chapter 17' - benjamin


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
chapter 17

Chapter 17

Alcohol & Phenol

ROH & ArOH

Chapter 17 - Alcohol & Phenol

chapter 172
Chapter 17
  • Naming
  • Properties
  • Synthesis
  • Reactions

Chapter 17 - Alcohol & Phenol

slide3

5-methyl-2,4-hexanediol

Chapter 17 - Alcohol & Phenol

slide4

2-methyl-4-phenyl-2-butanol

Chapter 17 - Alcohol & Phenol

slide5

4,4-Dimethylcyclohexanol

Chapter 17 - Alcohol & Phenol

slide6

trans-2-Bromocyclopentanol

Chapter 17 - Alcohol & Phenol

slide7

4-Bromo-3-methyl-phenol

Chapter 17 - Alcohol & Phenol

slide8

(o = ortho(1,2), m = meta(1,3), p = para(1,4))

2-(2-Hydroxyethyl)phenol

o-(2-Hydroxyethyl)phenol

Chapter 17 - Alcohol & Phenol

chapter 179
Chapter 17
  • Naming
  • Properties
  • Synthesis
  • Reactions

Chapter 17 - Alcohol & Phenol

properites
Properites
  • Hydrogen bonding
  • Acidity and Basicity

Chapter 17 - Alcohol & Phenol

slide11

Hydrogen Bonding

H2O

HF

H2Te

NH3

H2Se

H2S

SnH4

…extrapolation

GeH4

SiH4

CH4

1. Water, HF, and NH3 show unusually high bp.

2. Dotted lines depict bp if there were no H-bonding.

3. All others follow normal trend.

Chapter 17 - Alcohol & Phenol

slide12

Chemical Bond,

intramolecular,

150 - 600 kJ/mol

Hydrogen bond,

intermolecular,

4 - 25 kJ/mol

Hydrogen Bonding in Water

+

+

+

+

--

--

+

+

--

+

+

+

--

+

--

Chapter 17 - Alcohol & Phenol

slide13

Hydrogen Bonding in Alcohol

+

+

-

-

+

-

+

+

-

-

Chapter 17 - Alcohol & Phenol

hydrogen bonding and boiling point
Hydrogen Bonding and Boiling Point

Chapter 17 - Alcohol & Phenol

properites15
Properites
  • Hydrogen bonding
  • Acidity and Basicity

Chapter 17 - Alcohol & Phenol

acidity basicity
Acidity & Basicity

Like water, alcohol can act as an acid or as a base.

base

acid

oxonium ion

alkoxide ion

acid

base

phenoxide ion

Chapter 17 - Alcohol & Phenol

slide17

1. Why does the reaction shift to the right?

2. Why is phenoxide ion stable?

3. Why is phenol acidic (compare to water)?

…….

Chapter 17 - Alcohol & Phenol

resonance stability acid strength

2. Stable anion implies the following reaction will proceed to the right,

Resonance, Stability, Acid Strength

1. Resonance structures implies stability.

3. Stable anion also implies that phenol is a stronger acid than water.

Chapter 17 - Alcohol & Phenol

slide19

Substituted Phenol

Which one is more acidic and why?

Chapter 17 - Alcohol & Phenol

slide20

To examine the acid strength,

Chapter 17 - Alcohol & Phenol

resonance stability acid strength21

1.

has more resonance structures than

,so it is more stable.

.

3. Since 1 is true, that means

is more reactive than

.

4. Since 3 is true,

is more acidic than

Resonance, Stability, Acid Strength

2. Fifth structure shows that nitro is an electron-withdrawing group.

5. See page 663 for para position effect.

Chapter 17 - Alcohol & Phenol

resonance stability acid strength22

pKa

9.95

10.17

Resonance, Stability, Acid Strength

1. Phenol is more acidic than p-methylphenol.

2. pKa indicates that CH3– is an electron-donating group.

Chapter 17 - Alcohol & Phenol

arrange the order of acidity from highest to lowest of the following compounds and explain why
Arrange the order of acidity (from highest to lowest) of the following compounds and explain why.

Chapter 17 - Alcohol & Phenol

slide24

Answer Key

4-methoxylphenol

(least acidic)

phenol

4-nitrobenzylphenol

(most acidic)

Reason: The nitro- on4-nitrobenzylphenol is an electron-withdrawing group

which enhances the aciditiy compare to phenol. The methoxy- of

4-methoxylphenol is an electron-donating group, thus it is less acidic than

phenol.

Chapter 17 - Alcohol & Phenol

chapter 1725
Chapter 17
  • Naming
  • Properties
  • Synthesis
  • Reactions

Chapter 17 - Alcohol & Phenol

synthesis
Synthesis
  • Hydroboration, Oxymercuration, Hydroxylation.
  • Reaction with peroxide.
  • Reduction of carbonyl compounds.

Chapter 17 - Alcohol & Phenol

slide27

HX

ether

X2

CH2Cl2

KMnO4, H3O+

X2

O3

H2O(xs)

Zn/H3O+

HgAc2, H2O/THF

CH2I2

NaBH4

Zn(Cu) ether

BH3, THF

CHCl3

H2O2, OH-

KOH

H2

OsO4

NaHSO4, H2O

Pd or Pt

M

halogenation

anti

halohydrination

oxidation

M

anti

oxymercuration

M

oxidation

Alkene

hydroboration

non-M

syn

Simmons-Smith

syn

hydrogenation

syn

carbenation

syn

syn

hydroxylation

Chapter 17 - Alcohol & Phenol

synthesis28
Synthesis
  • Hydroboration, Oxymercuration, Hydroxylation.
  • Reaction with peroxide.
  • Reduction of carbonyl compounds.

Chapter 17 - Alcohol & Phenol

also from alkene
Also from alkene

1-Methyl-1,2-epoxy-

cyclohexane

1-Methyl-

trans-1,2-cyclohexanol

Chapter 17 - Alcohol & Phenol

synthesis30
Synthesis
  • Hydroboration, Oxymercuration, Hydroxylation.
  • Reaction with peroxide.
  • Reduction of carbonyl compounds.

Chapter 17 - Alcohol & Phenol

reduction of aldehyde ketone
Reduction of Aldehyde & Ketone

Reducing Agents:

1. NaBH4, ethanol, H+

2. LiAlH4, ether, H+

Chapter 17 - Alcohol & Phenol

reduction of carboxylic acid ester
Reduction of Carboxylic Acid & Ester

Reducing Agents:

LiAlH4, ether, H+

Chapter 17 - Alcohol & Phenol

carbonyl compounds grignard reagent
Carbonyl compounds + Grignard reagent

Chapter 17 - Alcohol & Phenol

chapter 1734
Chapter 17
  • Naming
  • Properties
  • Synthesis
  • Reactions

Chapter 17 - Alcohol & Phenol

reactions
Reactions
  • Dehydration  alkenes
  • With HX  alkyl halides
  • With Tosylates
  • Oxidation - 1o, 2o, & 3o
  • Protection of alcohol

Chapter 17 - Alcohol & Phenol

synthesis of alkene
Synthesis of Alkene

From halides - dehydrohalogenation (minus HX):

Elimination

From alcohol - dehydration (minus H2O):

Chapter 7 slide 5

Chapter 17 - Alcohol & Phenol

dehydration
Dehydration

1. Watch for Zaitsev’s rule!!!

2. Only 3o alcohols are readily dehydrated with acid.

3. 2o alcohols are dehydrated under mild basic condition.

4. Alcohol dehydration via E2.

Chapter 17 - Alcohol & Phenol

dehydration mechanism
Dehydration Mechanism

E1

Chapter 17 - Alcohol & Phenol

reactions39
Reactions
  • Dehydration  alkenes
  • With HX  alkyl halides
  • With Tosylates
  • Oxidation - 1o, 2o, & 3o
  • Protection of alcohol

Chapter 17 - Alcohol & Phenol

alcohol to alkyl halide
Alcohol to Alkyl Halide

SN2

Chapter 17 - Alcohol & Phenol

reactions41
Reactions
  • Dehydration  alkenes
  • With HX  alkyl halides
  • With Tosylates
  • Oxidation - 1o, 2o, & 3o
  • Protection of alcohol

Chapter 17 - Alcohol & Phenol

p toluenesulfonyl chloride p toscl
p-toluenesulfonyl Chloride (p-TosCl)

ROTos

Chapter 17 - Alcohol & Phenol

with tosylate
With Tosylate

C–O broken

Inversion

Inversion

R

S

R

C–O not broken

No inversion

Inversion

S

R

R

Chapter 17 - Alcohol & Phenol

reactions44
Reactions
  • Dehydration  alkenes
  • With HX  alkyl halides
  • With Tosylates
  • Oxidation - 1o, 2o, & 3o
  • Protection of alcohol

Chapter 17 - Alcohol & Phenol

oxidation primary alcohol

aldehyde

Pyridinium chlorochromate

carboxylic acid

(an aldehyde may be an intermediate but usually can’t be isolated.)

Oxidation - Primary Alcohol

Chapter 17 - Alcohol & Phenol

oxidation secondary alcohol
Oxidation - Secondary Alcohol

Chapter 17 - Alcohol & Phenol

oxidation tertiary alcohol
Oxidation - Tertiary Alcohol

No Reaction

Chapter 17 - Alcohol & Phenol

reactions48
Reactions
  • Dehydration  alkenes
  • With HX  alkyl halides
  • With Tosylates
  • Oxidation - 1o, 2o, & 3o
  • Protection of alcohol

Chapter 17 - Alcohol & Phenol

protection of alcohol
Protection of Alcohol

“It often happens, particularly during synthesis of complex

molecules, that one functional group in a molecule

interferes with an intended reaction on a second functional

group elsewhere in the same molecule.” - p 682.

Chapter 17 - Alcohol & Phenol

trimethylsilyl tms ether

Triethylamine

Trimethylsilyl (TMS) ether

Chlorotrimethylsilane

TMS ether

ROH is now blocked or protected!!!

Chapter 17 - Alcohol & Phenol

step 1 adding protection group
Step 1: Adding Protection Group

+

Chapter 17 - Alcohol & Phenol

step 2a carrying out reaction
Step 2a: Carrying Out Reaction

Chapter 17 - Alcohol & Phenol

step 2b carrying out reaction
Step 2b: Carrying Out Reaction

+

Chapter 17 - Alcohol & Phenol

step 3 removing protection group
Step 3: Removing Protection Group

+

Chapter 17 - Alcohol & Phenol