2-methyl-2-butanol is a tertiary alcohol. To understand why, let’s look at the definition of alcohols:
- A primary alcohol has the hydroxyl group (-OH) attached to a carbon atom that is connected to only one other carbon.
- A secondary alcohol has the hydroxyl group on a carbon that is connected to two other carbons.
- A tertiary alcohol has the hydroxyl group on a carbon that is connected to three other carbons.
In the case of 2-methyl-2-butanol, the structure can be drawn as follows:
The carbon to which the -OH group is attached (the second carbon in the chain) is connected to three other carbon atoms (the two methyl groups and the butyl chain). Therefore, it is classified as a tertiary alcohol.