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Basic IUPAC Organic Nomenclature

Ethers

Nomenclature
Formula
3D structure
Functional class name = alkyl alkyl ether e.g. ethyl methyl ether

Substituent prefix = alkoxy-   e.g. methoxyethane


Examples of how each of the types of nomenclature are applied are given below. No one method is more correct than the other, but some guidance on the common practices is given. 

Note : the examples chosen are to illustrate the naming subsystem. 

In practice, these examples would probably all be named as alkyl alkyl ethers.


"Simple" ethers
  • Functional group is a simple ether, therefore use alkyl alkyl ether
  • First substituent is C1 alkane therefore alkyl = methyl
  • Second substituent is C2 alkane therefore alkyl = ethyl
ethyl methyl ether
CH3CH2OCH3

  • Functional group is a simple ether, therefore use alkyl alkyl ether
  • Both substituents are C2 alkane therefore alkyl = ethyl
  • Since there are two alkyl groups, multipler = di
diethyl ether
CH3CH2OCH2CH3


 "Intermediate" ethers
  • Hydrocarbon structure is an alkane therefore -ane
  • The longest continuous chain is C3 therefore root = prop
  • Substituent is C1 alkane therefore alkyl = methyl
  • The first point of difference rule requires numbering from the right as drawn to make the group locant 1-
1-methoxypropane

CH3CH2CH2OCH3

  • Hydrocarbon structure is an alkane therefore -ane
  • The longest continuous chain is C3 therefore root = prop
  • Substituent is C1 alkane therefore alkyl = methyl
  • Numbering makes the group locant 2-
2-methoxypropane
CH3CH(OCH3)CH3


"Complex" ethers

  • Hydrocarbon structure is an alkane therefore -ane
  • Functional group is an ether, therefore prefix = -oxa-
  • The longest continuous chain (including the O)  is 5 therefore root = pent
  • Numbering from the left as drawn to make the oxa group locant 2-
2-oxapentane
CH3OCH2CH2CH3



organic chemistry ©Dr. Ian Hunt, Department of Chemistry University of Calgary