alcohols, amines, ethers and epoxides: chapter 10

Chapter 10 1

Alcohols, Amines, Ethers and Alcohols, Amines, Ethers and Epoxides:Epoxides:Chapter 10Chapter 10

Chapter 10 2

Contents of Chapter 10 Naming Alcohols Substitution and Dehydration of

Alcohols Oxidation of Alcohols Naming Ethers Epoxides

Chapter 10 3

Naming Alcohols Find longest carbon chain containing the

alcohol. OH gives attached carbon lowest possible

number. Break ties with other substituents if

necessary. Substituents are listed in alphabetical order.

Chapter 10 4

Examples

CH3CH2CH2CH2CHCH2OHCH2CH2CH3

123456

1 2 3

CC

1. Determine longest chain with OHBlue chain is longer; however,Red chain contains OH

2. Name: 2-propyl-1-hexanol

Notice that numbering starts at alcohol group

Chapter 10 5

Examples

Chapter 10 6

Conversion of Alcohols to Alkyl Halides

Hydrogen halide reactions can be SN1 or SN2

Chapter 10 7

Mechanism of SubstitutionSecondary and tertiary alcohols undergo SN1 reaction.

OHH3C

H3CH3C BrH

OH3C

H3CH3C H

H

CH3

H3C CH3

CH2

H3C CH3

Br- HBr

Br

carbocation

tert-butanol

tert-butyl chloride

- H2O

Chapter 10 8

Mechanism of SubstitutionPrimary alcohols undergo SN2 reaction. Primary carbocations are too unstable to be formed.

OH1-butanol

BrHOH

H

Attack from back-side

OH

H

Br

Br1-bromobutane

- H2O

Chapter 10 9

Dehydration of Alcohols

Zaitsev’s Rule is followed whenever possible

Chapter 10 10

Dehydration of Alcohols

Chapter 10 11

Cr6+ Oxidation of Alcohols

Acidic hexavalent chromium removes all H’s makes C-O bondsPCC removes only one H and makes an aldehyde from a 10 alcohol

Chapter 10 12

Cr6+ Oxidation of Alcohols

Chapter 10 13

Nomenclature of Ethers Common Name: Name of alkyl substituents

followed by “ether”O

methyl ethyl ether

O

12

3

1-ethoxy-2-methylpropane

IUPAC

Parent alkyl compound with RO substituent. “-yl” is then replaced by “oxy”

methyl isopropyl etherO

2-methoxy-butaneO1

2

34

Chapter 10 14

Substitution Reactions of Ethers

Ethers can be cleaved only with HI and HBr, not HCl SN1 and SN2 reactions give opposite regioselectivity;

H goes on bulky C in SN2, and less-hindered in SN1

Chapter 10 15

Epoxides