What is an example of an acid-catalyzed alkoxylation?
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.
- Protonation of the alkene to create reaction conditions in which an alcohol can be a good nucleophile.
- Nucleophilic backside-attack of the carbocation intermediate.
- Removal of the attached alkoxide's proton (
#"pKa" ~~ -3.6#) to regenerate the catalyst and form the product(s).