01Classification & Oxidation
Primary, secondary and tertiary alcohols
This section covers how alcohols are classified from the number of carbon atoms bonded to the carbon that carries the hydroxy group.
Classifying an alcohol
Find the carbon atom directly joined to the group, then count how many other carbon atoms are bonded directly to it.
1
Primary
The hydroxy-bearing carbon has one carbon attached to it.
Example: propan-1-ol
2
Secondary
The hydroxy-bearing carbon has two carbons attached to it.
Example: propan-2-ol
3
Tertiary
The hydroxy-bearing carbon has three carbons attached to it.
Example: 2-methylpropan-2-ol
Where several groups occur in the same molecule, classify each hydroxy-bearing carbon separately.
Exam Tip: Base the classification only on the carbon directly carrying . Count its carbon neighbours, not the oxygen or hydrogen atoms.