Question

Question: Draw a stepwise mechanism for the conversion of hex-5-en-1-ol to the cyclic ether A.

Short answer

Answer

Step-by-step solution

Intramolecular reaction  

Intramolecular cyclization occurs due to the presence of one Lewis donor group and one pi acceptor group. The reactivity of intramolecular cyclization is enhanced by the presence of acids

Formation of cyclic ethers

The intramolecular reaction of oxygen with alkene (donation of non-bonding electrons of oxygen to the vacant pi orbital of alkene) leads to cylic ether.

Explanation

The alkene first reacts with sulfuric acid to generate the carbocation. Next, the OH group attacks the positive charge on carbon and cyclizes.

The mechanism is shown below:

Reaction mechanism