Chemistry 2100

Lecture 4

ALCOHOLSALCOHOLSETHERSETHERSTHIOLSTHIOLS

thiol / mercaptan(sulfhydryl)

alcohol

HS

R

ether

R'O

R

HO

R

Common Nomenclature

• alkyl "alcohol"

• dialkyl "ether"

IUPAC Nomenclature

• "e" "ol"

• locator numbers

Alcohols

Alcohol:Alcohol: A compound that contains an -OHOH (hydroxyl) group(hydroxyl) group bonded to a tetrahedral carbon.– Methanol, CH3OH, is the simplest alcohol.

Nomenclature1. Select the longest carbon chain that contains the -OH

group as the parent alkane and number it from the end that gives the -OH the lower number.

2. Change the ending of the parent alkane from -ee to -olol and use a number to show the location of the -OH group; for cyclic alcohols, the carbon bearing the -OH group is carbon-1.

3. Name and number substituents and list them in alphabetical order.

Nomenclature

– In the IUPAC system, a compound containing two hydroxyl groups is named as a dioldiol, one containing three hydroxyl groups as a trioltriol, and so forth.

– IUPAC names for diols, triols, and so on retain the final "-e" in the name of the parent alkane.

– We commonly refer to compounds containing two hydroxyl groups on adjacent carbons as glycolsglycols.CH3CHCH2

HO OHCH2CH2OH OH

CH2CHCH2

OH OHOH1,2-Ethanediol

(Ethylene glycol)1,2-Propanediol

(Propylene glycol)1,2,3-Propanetriol

(Glycerol, Glycerin)

Physical PropertiesAlcohols are polar molecules. – The C-O and O-H bonds are both polar

covalent.

Physical Properties

In the liquid state, alcohols associate by hydrogen bonding.

CH3OH 65° CH3CH2CH2OH 97°

CH3CH3 -88° CH3CH2CH2CH3 0°

CH3Cl -24° CH3CH2CH2Cl 46°

PhOH 182° CH3CH2CH2CH2OH 118°

PhCH3 110° (CH3)2CHCH2OH 108°

PhCl 132° (CH3)3COH 83°

boiling points (°C)

solubility (g / 100 mL H2O)

∞

∞

8.3

2.4

0.6

0.05

7.8

10.0

∞

3.6

CH3CH2OH

CH3CH2CH2OH

CH3CH2CH2CH2OH

CH3CH2CH2CH2CH2OH

CH3CH2CH2CH2CH2CH2OH

CH3CH2CH2CH2CH2CH2CH2CH2OH

CH3CH2OCH2CH3

(CH3)2CHCH2OH

(CH3)3COH

C6H11OH

zymase

sucrose ethanol

2O

2O

C12H22O11 + H

4 C2H5OH + 4 CO

Preparing AlcoholsFermentation

Alkene Hydration

+H2SO4

H OH

H2OCC C C

OHH

H

H H

H H

H H

H

DehydrationCH3CH2OH

H2SO4 CH2=CH2 H2O+Ethanol Ethylene

180°C

OHH2SO4 H2O140°C

Cyclohexanol Cyclohexene

+

CH3CCH3

OH

CH3H2SO4 CH3C=CH2

CH3

H2O50°C

2-Methyl-2-propanol (tert -Butyl alcohol)

2-Methylpropene (Isobutylene)

+

Oxidation of Alcohols

(1°)

(2°)

N

H H

NAD +

H+

CH3 C H

O

NAD H

Ad Ad

CH3

H

C

O

H

H

N

H

••

[O]

N

H H

NAD +

H+

CH3 C H

O

NAD H

Ad Ad

CH3

H

C

O

H

H

N

H

••

[O]

N

H H

NAD +

H+

CH3 C H

O

NAD H

Ad Ad

CH3

H

C

O

H

H

N

H

••

[O]

N

H H

NAD +

H+

CH3 C H

O

NAD H

Ad Ad

CH3

H

C

O

H

H

N

H

••

[O]

N

H H

NAD +

H+

CH3 C H

O

NAD H

Ad Ad

CH3

H

C

O

H

H

N

H

••

[O]

N

H H

NAD +

H+

CH3 C H

O

NAD H

Ad Ad

CH3

H

C

O

H

H

N

H

••

[O]

N

H H

NAD +

H+

CH3 C H

O

NAD H

Ad Ad

CH3

H

C

O

H

H

N

H

••

[O]

N

H H

NAD +

H+

CH3 C H

O

NAD H

Ad Ad

CH3

H

C

O

H

H

N

H

••

[O]

Ethers

Common Nomenclature

• dialkyl "ether"• dialkyl "ether"

• "alkoxy"

IUPAC Nomenclature

(diethyl) etherbp 36°C

7.8 g/100 mL

1-butanol bp 118°C

8.3 g/100 mL

pentanebp 36°C

H C C O C C H

H

H

H

H

H

H

H

H

H C C C C C H

H

H

H

H

H

H

H

H

H

H

H C C C C O H

H

H

H

H

H

H

H

H

isoflurane

F C

F

O

F

C C

Cl

H

F

F

F

halothane enflurane

F C C

F

F

Br

Cl

H

F C

H

O

F

C C

F

F

Cl

F

H

Anesthetics

Thiols / Mercaptans

Naming thiols

Alkane + thiol

1-propanethiol 2-propene-1-thiol

CH3CH2OH (bp 78°C) CH3OCH3 (bp -24°C)

CH3CH2SH (bp 35°C) CH3SCH3 (bp 37°C)

[O]R S R'

O

••

• •

• •R S R'

[O]R S R'

O

Osulfoxidesulfide (thioether)

sulfone

Oxidation

cysteine

C OH

O

CH

NH2

CH2SH

S S

S S

[H]

[O]

SH

SH

SH

SH

S

S

S

S

S S

S S

[H]

[O]

S

S

S

S

SH

SH

SH

SH

[H]

[O]

S

S

S

S

SH

SH

SH

SH

S S

S S

-helix

-helix

-helix

-helix

-helix

-helix

-helix

-helix

-helix

-pleated sheet

-helix

-helix-pleated sheet

-pleated sheet

salt bridge

NH3

+

-helix

-helix-pleated sheet

-pleated sheet

C-O

O

hydrogenbond

CH2 O

H

CH2O

H

salt bridge

NH3

+

-helix

-helix-pleated sheet

-pleated sheet

C-O

O

hydrogenbond

CH2 O

H

CH2O

H

NH

H

C

OH

O

hydrogenbond

salt bridge

NH3

+

-helix

-helix-pleated sheet

-pleated sheet

C-O

O

hydrogenbond

CH2 O

H

CH2O

H

NH

H

C

OH

O

hydrogenbond

salt bridge

NH3

+

CH2

HO

hydrophilicinteractionto water

CH2

C

NH2

O

CH2

HO

-helix

-helix-pleated sheet

-pleated sheet

C-O

O

CH2

CH2

hydrophobicinteraction

hydrogenbond

CH2 O

H

CH2O

H

NH

H

C

OH

O

hydrogenbond

salt bridge

NH3

+

CH2

HO

hydrophilicinteractionto water

CH2

C

NH2

O

CH2

HO

-helix

-helix-pleated sheet

-pleated sheet

C-O

O

CH

CH3 CH3

CH3

CH2

CH2

hydrophobicinteraction

hydrogenbond

CH2 O

H

CH2O

H

NH

H

C

OH

O

hydrogenbond

salt bridge

NH3

+

CH2

HO

hydrophilicinteractionto water

CH2

C

NH2

O

CH2

HO

-helix

-helix-pleated sheet

-pleated sheet

C-O

O

CH

CH3 CH3

CH3

CH2

CH2

hydrophobicinteraction

S

S

S

Sdisulfide

bond

hydrogenbond

CH2 O

H

CH2O

H

NH

H

C

OH

O

hydrogenbond

salt bridge

NH3

+

CH2

HO

hydrophilicinteractionto water

CH2

C

NH2

O

CH2

HO

-helix

-helix-pleated sheet

-pleated sheet

C-O

O