How are alcohols named?
The IUPAC allows several nomenclature systems for the alcohols listed below:
- Substitutive nomenclature: it is named with the prefix indicating the number of carbons followed by the termination -ol (recommendation C-201.1). To place the function in a chain, the lowest locator is used.
- Radical-function nomenclature (only applicable to simple alcohols): this consists of first citing the name of the function (alcohol) and then the name of the radical as if it were an adjective (recommendation C-201.3).
In complex molecules only the first nomenclature system is used. When acting as a substituent: the prefix hydroxy is used (recommendation C-201.3). Alcohols with two neighboring hydroxyl groups are given the generic name glycols. Some common names are retained (recommendation C-201.4).
- Radicals derived from alcohols: radicals derived from alcohols of the R-O- type are named by adding the ending -oxy to the name of the radical (recommendation C-205.1). For simpler radicals, abbreviations are often used and are indicated in the figure in parentheses.
Salts derived from these radicals are assigned the same name as the radical ending in -de followed by the name of the cation (recommendations C-206.1 and C-206.2).
Nomenclature of Phenols
Generically, they are arenes that have at least one -OH group. The first term in the series is phenol, with an -OH attached to benzene, which gives this family of compounds its name.
The OH group in an aromatic ring does not have a high priority. Therefore it is found as the main group (-ol) but more often as a secondary one (-hydroxy-).
They are named like the corresponding alcohols, with the ending -ol added to the name of the hydrocarbon. However, the prefix hydroxy- can also be used together with the name of the hydrocarbon (recommendation C-202.1).
Some of these compounds retain common or trivial names (indicated here in parentheses) (recommendation C-202.2).
The corresponding Ar-O-type radicals are named similarly to the alcohol derivatives (recommendation C-205.1).
The salts derived from these radicals are named analogously to the corresponding salts of the alcohols.