What is an example of an acid-catalyzed alkoxylation?

Question

Ryan Andrews · Accepted Answer

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).

Ryan Andrews · Answer

undefined An example of an acid-catalyzed alkoxylation is the Williamson ether synthesis, where an alkoxide ion attacks the carbon of a haloalkane under acidic conditions to form an ether.