Is acid-catalyzed hydration stereoselective?
Acid-catalyzed hydration of alkenes is not stereoselective.
The steps in the mechanism are:
- Protonation of the π bond to form a carbocation
- Addition of water to the carbocation to form an oxonium ion
- Deprotonation of the oxonium ion to form an alcohol.
This carbocation formed in Step 1 is
That means that the reaction is not stereoselective.
If the carbon bearing the OH group is chiral, we get a mixture of (R) and (S) alcohols.