Acid-Catalyzed Hydration

Acid-catalyzed Hydration

Acid-catalyzed hydrations reactions:

1. occur in multiple steps and are classified as an "ionic" reactions
2. proceed via a carbocation intermediate
3. have Markovnikov addition for a regiochemical outcome (Markovnikov addition has the higher priority group added to the more substituted carbon atom)
4. have addition at the carbocation intermediate from top and bottom face with 50/50 distribution to give mixed sterechemical distribution (a racemic mixture if there is only one stereocentre)

Steps of a Acid-catalyzed hydrations reaction:

1. addition of the hydrogen atom from the acid to the alkene to generate a carbocation
2. there may be carbocation rearrangement
3. nucleophilic attack of the water nucleophile onto the carbocation
4. deprotonation of the OH2+ group to regenerate the catalyst and generate the OH group

Mechanism:

Example: predict the product of the following acid-catalyzed hydration reaction below.