Question

What is an example of an acid-catalyzed alkoxylation?

Answer 1

The acid-catalyzed alkoxylation is an analogous reaction to the acid-catalyzed hydration (Markovnikov addition of water via acid catalysis), and can go as follows for a substituted alkene and a generic alcohol:

where the racemic mixture of the major or minor products can be written as a line bond instead of both the hash and wedge bonds.

(Had it not been racemic but uneven, a squiggly bond would have been the way to write it.)

The mechanism would go as follows:

with Markovnikov addition giving the major product.

1. Protonation of the alkene to create reaction conditions in which an alcohol can be a good nucleophile.
2. Nucleophilic backside-attack of the carbocation intermediate.
3. Removal of the attached alkoxide's proton (`"pKa" ~~ -3.6`) to regenerate the catalyst and form the product(s).