Organic Chemistry

PROBLEM 11

Draw the structures and provide systematic names for a–c by substituting a chlorine for a

hydrogen of methylcyclohexane:

a. a primary alkyl halide b. a tertiary alkyl halide c. three secondary alkyl halides

2.5 Nomenclature of Ethers

Ethersare compounds in which an oxygen is bonded to two alkyl substituents. If the

alkyl substituents are identical, the ether is a symmetrical ether. If the substituents

are different, the ether is an unsymmetrical ether.

The common name of an ether consists of the names of the two alkyl substituents

(in alphabetical order), followed by the word “ether.”The smallest ethers are almost

always named by their common names.

The IUPAC system names an ether as an alkane with an RO substituent. The sub-

stituents are named by replacing the “yl”ending in the name of the alkyl substituent

with “oxy.”

PROBLEM 12

a. Give the systematic (IUPAC) name for each of the following ethers:

2.CH 3 CH 2 OCH 2 CH 3 4. CH 3 CH 2 CH 2 OCH 2 CH 2 CH 2 CH 3

OCH 3

CH 3 OCH 2 CH 3 CH 3 CH 2 CH 2 CH 2 CHCH 2 CH 2 CH 3

CH 3 CHOCH 2 CH 2 CH 2 CH 2 OCHCH 3

CH 3 CH 3

1,4-diisopropoxybutane

methoxy ethoxy

isopropoxy sec-butoxy

2-methoxybutane 1-ethoxy-3-methylpentane

tert-butoxy

CH 3 OCH 3 CH 2 OCH 3 CHO

CH 3

CH 3 CH 2 CHO

CH 3

CH 3 CHCH 2 CH 3

OCH 3

CH 3 CH 2 CHCH 2 CH 2 OCH 2 CH 3

CH 3

CH 3 CO

CH 3

CH 3

CH 3 CHOCHCH 2 CH 3

CH 3

CH 3

sec-butyl isopropyl ether

CH 3

CH 3 CHCH 2 OCCH 3

CH 3

tert-butyl isobutyl ether

CH 3

CH 3 OCH 2 CH 3

ethyl methyl ether

CH 3 CH 2 OCH 2 CH 3

diethyl ether

often called ethyl ether

CH 3 CHCH 2 CH 2 O

CH 3

cyclohexyl isopentyl ether

RRO RR ́

a symmetrical ether

O

an unsymmetrical ether

74 CHAPTER 2 An Introduction to Organic Compounds

Chemists sometimes neglect the prefix

“di” when they name symmetrical

ethers. Try not to make this oversight a

habit.

Tutorial:

Nomenclature of ethers

dimethyl ether

diethyl ether

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