Naming Alcohols
(Chemical) Definition of Alcohols:
Alcohols are organic chemical compounds that include the -hydroxyl functional group:
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That is, alcohols are a class or category of organic chemical compounds that include a part consisting of an oxygen atom (attached to one of the carbon atoms in the molecule), to which a single hydrogen atom is also attached.
Alcohol molecules can vary in size up to very long molecules most of which consist of carbon atoms attached to each other and also to hydrogen atoms.
When the structures of alcohols are drawn out in textbooks, on websites or in course materials, the covalent bond between the oxygen and the hydrogen is not always shown, but of course it is always present.
That is, the hydroxyl group may be represented equivalently as:
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Names of Alcohols in General
Alcohols are named according to the same system as other organic compounds, with the suffix -ol used to designate the presence in the molecule of a hydroxyl group.
The first step is to consider the number of carbon atoms forming a chain. If they are attached together in a linear (i.e. unbranched) configuration then the number of carbon atoms is indicated according to the same system as used for naming alkanes (see the examples listed in the table below).
However, if the carbon atoms do not form a linear chain but include branches, the longest linear chain of carbon atoms within the molecule determines the base of the name of the compound, onto which is added information about the branches incl. their lengths in terms of the number of carbon atoms in each branch (i.e. methyl- indicates a branch consisting of just one carbon atom attached to the main chain, ethyl- indicates a branch of two carbon atoms in length, etc.) and their positions along the longest linear carbon chain (e.g. attached to the 2nd carbon, 3rd carbon, etc.).
The simplest linear alcohols are named and their structures drawn in the following table.
More complex alcohol molecules follow afterwards.
Names and Structures of simple Linear Alcohols
The homologous series of linear alcohols with the -hydroxyl group attached to the first (=last!) carbon atom is shown below.
Number carbons in chain |
Name |
Simple Structure |
Other Names = Synonyns
(*Examples not complete lists) |
and simple formula |
showing bond types but not accurate bond angles |
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1 |
|
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- methyl alcohol
- methyl hydrate
- methyl hydroxide
- methylol
- metanol
- carbinol
- carbonal
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2 |
ethanol (C2H5OH) |
CH3CH2OH |
|
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- ethyl alcohol
- ethyl hydroxide
- ethylol
- hydroxyethane
- 1-hydroxyethane
- methylcarbinol
- and many more !
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3 |
propanol (C3H7OH) |
CH3CH2CH2OH |
|
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- propan-1-ol
- 1-propanol
- n-propanol
- propyl alcohol
- n-propyl alcohol
- propylic alcohol
- ethyl carbinol
- optal
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4 |
butanol (C4H9OH) |
CH3CH2CH2CH2OH |
|
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- butan-1-ol
- 1-butanol
- n-butanol
- n-butan-1-ol
- 1-hydroxybutane
- propyl carbinol
- 1-butyl alcohol
- butyl hydroxide
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5 |
pentanol (C5H11OH) |
CH3CH2CH2CH2CH2OH |
|
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- pentan-1-ol
- 1-pentanol
- n-pentanol
- n-pentan-1-ol
- butyl carbinol
- amyl alcohol
- amylol
- C5 alcohol
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6 |
hexanol (C6H13OH) |
CH3CH2CH2CH2CH2CH2OH |
|
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- hexan-1-ol
- 1-hexanol
- n-hexanol
- n-hexan-1-ol
- pentyl carbinol
- caproic alcohol
- caproyl alcohol
- amylcarbinol
- alcohol C-6
- c6 alcohol
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7 |
heptanol (C7H15OH) |
CH3CH2CH2CH2CH2CH2CH2OH |
|
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- heptan-1-ol
- 1-heptanol
- n-heptanol
- n-heptan-1-ol
- heptyl alcohol
- n-heptyl alcohol
- hexyl carbinol
- alcohol C-7
- hydroxy heptane
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8 |
octanol (C8H17OH) |
CH3CH2CH2CH2CH2CH2CH2CH2OH |
|
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- octan-1-ol
- 1-octanol
- n-octanol
- n-octan-1-ol
- octyl alcohol
- n-octyl alcohol
- capryl alcohol
- caprylic alcohol
- heptyl carbinol
- alcohol C-8
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9 |
nonanol (C9H19OH) |
CH3CH2CH2CH2CH2CH2CH2CH2CH2OH |
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- nonan-1-ol
- 1-nonanol
- n-nonanol
- n-nonan-1-ol
- nonyl alcohol
- n-nonyl alcohol
- nonalol
- octyl carbinol
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10 |
decanol (C10H21OH) |
CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2OH |
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Why stop at ten carbon atoms (in the chain) ? It doesn't ... there are more similar linear alcohols. .... We stopped here due to page width ! |
Important Note: *The synonyms indicated for compounds listed above are just some examples of alternative names found online and believed to have been used to refer to the substance indicated. They have not all been verified and may include common (non-scientific) names, trade names specific to particular suppliers, and perhaps errors. The purpose of these lists is to give a general indication of the range of names by which alcohols are known - both generally, and specifically.
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Note:
This is one of many pages about types of organic compounds in our Organic Chemistry Section. Similar and related pages describe hydrocarbons, alkanes, haloalkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons (arenes), alcohols, esters, ethers, aldehydes, ketones, carboxylic acids, acid chlorides, acid anhydrides, azo dyes, amines, amides, nitriles, amino acids (chemistry), peptides, proteins (chemistry), polypeptides and others. If you need further information ask your chemistry tutor.
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