# How can you identify primary alcohol?

Apr 7, 2016

By the presence of the $C {H}_{2} O H$ group.

#### Explanation:

The alcoholic derivative of a primary methyl group is a so-called primary alcohol. Ethyl alcohol, ${H}_{3} C - C {H}_{2} O H$ is certainly a primary alcohol. So if you see 2 hydrogens on the alcoholic ipso carbon, you know you have a primary alcohol. Other examples include $1 - \text{propanol}$ and $1 - \text{butanol}$

On the other hand, if there is only the one hydrogen on the ipso carbon, then you have a secondary alcohol: isopropyl alcohol ${\left({H}_{3} C\right)}_{2} C H O H$ is the examplar.

No prizes for guessing that for the tertiary alcohol, the ipso carbon has no hydrogens. Tertiary butanol, ${\left({H}_{3} C\right)}_{3} C - O H$ is an example.

Note that methyl alcohol, ${H}_{3} C O H$ is to all intents and purposes a primary alcohol. Some texts place methyl alcohols, and methyl derivatives, in a special class (which they are because the ipso carbon bears 3 hydrogens!) because they are more reactive than even ethyl alcohol.