Alcohols are classified as primary (1o), secondary (2o), or tertiary (3o) depending on the number of alkyl substituents attached to the carbon bonded to the O-H group.
methyl alcohol | primary (1o) alcohol | secondary (2o) alcohol | tertiary (3o) alcohol |
For example, ethanol and propan-1-ol are primary alcohol's. Alcohols also have common names. The common names are provided in parenthesis.
Examples of secondary alcohols include,
Tertiary alcohols have 3 carbons bonded to the same carbon the -O-H is bonded to.
The IUPAC naming of alcohols is based on the name of the longest alkane/alkene (carbon) chain the hydroxyl group is bonded to.
4. When naming a cyclic structure with a hydroxyl group, the -OH is assumed to be on the first carbon.
5. When multiple alcohols are present use di, tri, etc before the ol. Also, when a prefix is used the -e is not removed from the parent chain name ex. 2,3-hexanediol
6. When an alkene and alcohol are present in a molecule it is named as follows (location of the alkene)-(prefix for the parent chain + en)-(location of the hydroxyl)-ol
Phenols are named using the rules for aromatic compounds discussed here. Note that -phenol is used as the ending rather than -benzene.