Question

Question: Bromoetherification, the addition of the elements of Br and OR to a double bond, is a common method for constructing rings containing oxygen atoms. This reaction has been used in the synthesis of the polyether antibiotic monensin (Problem 21.37). Draw a stepwise mechanism for the following intramolecular bromoetherification reaction.

Short answer

Answer

Step-by-step solution

Preparation of ether

Ethers contain the R-O-R’ functional group. Therefore, they can be prepared from alcohols. When any compound containing OH group attacks at any vacant position via mechanism, it gives ether.

Bromoetherification  

The term bromoetherification involves two processes—bromination and etherification. First, bromination occurs on the alkene, then intramolecular etherification occurs.

Explanation

The given compound has alkene and alcohol functional groups. First, bromination occurs on the alkene that is attacked by the alcohol group to form a five-membered cyclic ether

Bromoetherification