Chapter 13 Alcohols, Phenols, Ethers; Thiols and Sulfides

C C

H

H

OH

H

H

H C O C

H

H

H

H

H

H

AlcoholOH attached to sp3 carbon

EtherOxygen attached to two carbons

Ethanol bp = 74 °C

Dimethyletherbp = -27 °C

Fig. 13-1, p. 505

Alcohol introduction: Hydrogen Bonding

Alcohol introduction: Types of Alcohols

H C

H

H

OH H C

H

R

OH R C

H

R

OH R C

R

R

OH

R = sp3 carbon

methyl 1° 2° 3°

Alcohol introduction: reaction of sp3 oxygen with strong acids

H OH HCl+

H C

H

H

OH HCl+

C O C

H

H

H

H

H

H HCl+

Table 13-1, p. 506

Fig. 13-2, p. 508

Fig. 13-2, p. 508

[elim]

[sub] [sub]

Reactions

I. Substitution Reactions of Alcohols (review)

A. Conversion to alkyl halides

1. 1° & 3° with strong acid

Reactions

I. Substitution Reactions of Alcohols (review)

A. Conversion to alkyl halides

1. 1° & 3° with strong acid

Reactions

I. Substitution Reactions of Alcohols (review)

A. Conversion to alkyl halides

1. 1° & 3° with strong acid

2. 1° & 2° with SOCl2, pyridine

3. 1° & 2° with PBr3

.

p. 516

Substitution Reactions of alcohols : review

Reactions

I. Substitution Reactions of Alcohols (review)

A. Conversion to alkyl halides

1. 1° & 3° with strong acid

2. 1° & 2° with SOCl2, pyridine

3. 1° & 2° with PBr3

4. 1° & 2° with TsCl

Reactions

I. Substitution Reactions of Alcohols (review)

A. Conversion to alkyl halides

1. 1° & 3° with strong acid

2. 1° & 2° with SOCl2, pyridine

3. 1° & 2° with PBr3

4. 1° & 2° with TsClProblem: Enantiomeric products from same starting

material.

I. Substitution Reactions of Alcohols (cont.)

B. Formation of alkoxide ions

• pKa’s of alcohols

Reactions

Table 13-1, p. 506

I. Substitution Reactions of Alcohols (cont.)

B. Formation of alkoxide ions

• pKa’s of alcohols

1. Strong Bases (NaH, NaNH2)

2. Metals (Na0)

Reactions

I. Substitution Reactions of Alcohols (cont.)

B. Ether formation

1. Williamson Ether Synthesis

a. Formation of alkoxides

b. acyclic ethers

c. cyclic ethers (including

oxiranes)

2. Acid catalyzed ether formation

Reactions

I. Substitution Reactions of Alcohols (cont.)

C. Protection

1. introduction to protection

a. TMS ether

Reactions

II. Reactions of ethers.

A. Unstrained

B. Oxiranes (epoxides)

1. basic / nucleophilic conditions

•epoxy resins (what is in those two

tubes)

Reactions

Epoxy Resins

Epoxy ResinsTwo substances

Substance #1. diepoxy prepolymer.

C

CH3

CH3

O O C C

H

H

C

H

H

CH

O

H2C

OH

H

C

H

H

O C

CH3

CH3

O C

H

H

CH

CH2

O

n = 0 - 25epoxide epoxide

Epoxy ResinsTwo substances

Substance #1. diepoxy prepolymer.

C

CH3

CH3

O O C C

H

H

C

H

H

CH

O

H2C

OH

H

C

H

H

O C

CH3

CH3

O C

H

H

CH

CH2

O

n = 0 - 25epoxide epoxide

H2C CH

C

H

H

O C

CH3

CH3

O C

H

H

CH

CH2

O

n = 0

O

Epoxy ResinsTwo tubes

Substance #1. diepoxy prepolymer.

Substance #2. A polyamine (hardener, curing agent)

C

CH3

CH3

O O C C

H

H

C

H

H

CH

O

H2C

OH

H

C

H

H

O C

CH3

CH3

O C

H

H

CH

CH2

O

n = 0 - 25epoxide epoxide

H2C CH

C

H

H

O C

CH3

CH3

O C

H

H

CH

CH2

O

n = 0

O

H2N

HN

NH2

II. Reactions of ethers.

A. Unstrained

B. Oxiranes (epoxides)

1. basic / nucleophilic conditions

•epoxy resins (what is in those two

tubes)

2. acidic conditions

a. 1° & 2°

b. 3°

Reactions

II. Reactions of ethers.

A. Unstrained

B. Oxiranes (epoxides)

1. basic / nucleophilic conditions

•epoxy resins (what is in those two tubes)

2. acidic conditions

a. 1° & 2°

b. 3°

C. Allyl Aryl Ethers (The Claisen Rearrangement)

Reactions

Professor Rainer Ludwig Claisen (January 14, 1851 – January 5, 1930) was a famous German chemist best known for his work with condensations of carbonyls and sigmatropic rearrangements. He was born in Cologne as the son of a jurist and studied chemistry at the university of Bonn under August Kekulé, where he became a member of K.St.V. Arminia. He served in the army as a nurse in 1870-1871 and continued his studies at Göttingen University until he returned to the University of Bonn in 1872. He started his academic career at the same university in 1874. During his career he worked with other notable chemists, including the Noble Laureates Adolf von Baeyer and Emil Fischer. He died in 1930 in Godesberg am Rhein. In addition to the Claisen (1887) and Claisen-Schmidt (1881) condensations, the Claisen rearrangement (1912) and the Claisen isatin synthesis (1879), his name is associated with the Claisen flask and Claisen's rule which relates acidity to enolisation.

http://www.chem.qmul.ac.uk/rschg/biog.html

Reactions

III. Preparation of alcohols

From Alkenes (review)

1. Hydration (section 8.4)

a. H2O + HX (Markovnikov)

b. Oxymercuration (Markovnikov)

c. Hydroboration & oxidation (anti-

Markovnikov)

p. 509

Synthesis of alcohols : review

IV. Reduction and Oxidation reactions

• oxidation states

Reactions

Fig. 13-2, p. 508

Fig. 13-2, p. 508

[elim]

[sub] [sub]

Fig. 13-2, p. 508

[red]

[red][red]

[red]

Fig. 13-2, p. 508

[ox]

[ox]

[ox]

[ox]

V. Reduction and Oxidation reactions

• oxidation states

A. Alcohols From Carbonyl Compounds (reduction)

1. Hydride Reducing Agents

2. Grignard Reagents

i. TMS protection

Reactions

p. 557

Fig. 1, p. 557

V. Reduction and Oxidation reactions

• oxidation states

A. Alcohols From Carbonyl Compounds (reduction)

1. Hydride Reducing Agents

2. Grignard Reagents

B.Alcohols To Carbonyl Compounds (oxidation)

1. CrO3, H2SO4

2. K2Cr2O7

3. PCC

4. Dess – Martin Periodinane

Reactions

A better way to oxidize alcohol?

Cr(VI) reagents: 3–10 mg acutely poisonous for a 150-lb adult.

An investigation into an illegal release of Cr(VI) into drinking water was the basis of the film Erin Brockovich.

Chemical Reaction

2 K2Cr2O7 + 3 CH3CH2OH + 8 H2SO4

2 Cr2 (SO4)3 + 2 K2SO4 + 3 CH3COOH + 11 H2O

AgNO3

Fig. 13-9, p. 536

Spectroscopy of alcohols : Infrared

Fig. 13-10, p. 536

Spectroscopy of alcohols : Infrared

Fig. 13-11, p. 537

Spectroscopy of alcohols : NMR

p. 552

C5H10O

Fig. 13-12, p. 538

Spectroscopy of alcohols : Mass Spec