Question

What reagents to use to have E-3,4-dimethylpent-2-ene become E-3,4-dimethylpent-1-ene?

a) HBr
b) H2SO4
c) HCl
d) NaNH2

Answer 1

The reagent that can be used to convert E-3,4-dimethylpent-2-ene into E-3,4-dimethylpent-1-ene is HBr (hydrogen bromide). The reaction proceeds through the formation of a bromonium ion intermediate and the subsequent nucleophilic attack and dehydration steps.

Step-by-step explanation:

The reagent that can be used to convert E-3,4-dimethylpent-2-ene into E-3,4-dimethylpent-1-ene is HBr (hydrogen bromide).

The reaction proceeds as follows:

1. The HBr molecule adds across the double bond of E-3,4-dimethylpent-2-ene, resulting in the formation of a bromonium ion intermediate.
2. A nucleophilic attack by water on the bromonium ion leads to the formation of the alcohol compound E-3,4-dimethylpent-1-ol.
3. The final step involves the dehydration of E-3,4-dimethylpent-1-ol to yield E-3,4-dimethylpent-1-ene.