adding one equivalent of sulfuric acid to 2,4-hexadiene gives 2 possible products. Give the structure and write all steps in the reaction mechanism that explains how each product is formed
To understand the reaction mechanism and the formation of the products when adding one equivalent of sulfuric acid to 2,4-hexadiene, we need to consider the mechanism for an electrophilic addition reaction.
Step 1: Protonation
The first step involves the protonation of the π bond in 2,4-hexadiene. Sulfuric acid (H₂SO₄) acts as a proton source, donating a proton (H⁺) to the double bond. This protonation introduces a positive charge on the most substituted carbon atom, forming a resonance-stabilized carbocation intermediate.
Step 2: Nucleophilic Attack
After the π bond is broken, the nucleophile (H₂O) can attack the carbocation in two different ways due to the presence of two non-equivalent positions in the 2,4-hexadiene molecule. Let's examine the reaction pathway for each possibility:
Product 1:
In this case, the water nucleophile attacks the most highly substituted carbon (carbon with more alkyl groups attached). This leads to the formation of a tertiary carbocation intermediate.
Step 3: Rearrangement (Optional)
If there is a possibility of carbocation rearrangement, it may occur here to form a more stable carbocation. However, since no specific information is provided about the 2,4-hexadiene molecule's substituents, we'll assume no rearrangement takes place.
Step 4: Deprotonation
The negatively charged hydroxide ion (OH⁻) acts as a base and abstracts a proton from the carbocation, resulting in the formation of the first product.
Product 2:
Alternatively, the water nucleophile can attack the least substituted carbon atom in 2,4-hexadiene, forming a primary carbocation intermediate.
Step 3: Rearrangement (Optional)
If there is a possibility of carbocation rearrangement, it may occur here to form a more stable carbocation. However, with no specific information provided, we'll assume no rearrangement takes place again.
Step 4: Deprotonation
Similar to the previous mechanism, the negatively charged hydroxide ion (OH⁻) acts as a base and abstracts a proton from the carbocation, resulting in the formation of the second product.
It's important to note that without the specific substituents on the 2,4-hexadiene molecule, we cannot provide the exact structures of the products. However, understanding the reaction mechanism allows us to predict the possible products based on the regioselectivity of the nucleophilic attack.