Question: Draw the constitutional isomer formed in each reaction.

a.

b.

c.

d.

e.

f.

Constitutional isomers are structures with the same molecular formula but a different arrangement of groups.

The alkene generally undergoes the addition of electrophiles at the double bond. For example, the addition of borane on the double bond of alkene in the presence of hydrogen peroxide gives a less substituted alcohol isomer.

a. The given compound has substituted HCl.

Therefore, the H of HCl is substituted at the less substituted site, whereas the Cl is substituted at the more substituted site due to the formation of a stable carbocation.

Constitutional isomer formation

b. The given compound has H₂O substituted in the presence of H₂SO₄ . The anion of is substituted at the more substituted site due to the formation of a stable carbocation.

Constitutional isomer formation

c. The given compound has ^-OH substituted in the presence of hydrogen peroxide. As a result, a less substituted alcohol is formed.

Constitutional isomer formation

d. The given compound has ^-OH substituted at the more substituted site and Br substituted at the less substituted site of the double bond.

Constitutional isomer formation

e.The given compound has ^-OH substituted at the less substituted site of the double bond.

Constitutional isomer formation

f. The given compound has Br substituted on both sides of the double bond of the given compound. Therefore, vicinal dibromide is formed.

Constitutional isomer formation