Question

Dehydration of 2-methyl-2-pentanol forms one major and one minor organic product. Draw the structures, including hydrogen atoms, of the two organic products of this reaction.

Answer 1

Concepts and reason

Dehydration is a process where the water molecule is eliminated from a substrate with the help of dehydrating agents. ${{\rm{H}}_{\rm{2}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}$ is a good dehydrating reagent with heat. Moreover, according to Zaitsev’s rule, most substituted alkenes are more stable in elimination reactions.

Fundamentals

Dehydrating agent: a dehydrating agent is a substance, which causes the loss of water molecules from the substrate. These substances convert the poor leaving group into a good leaving group in the substrate by protonating them.

Zaitsev’s rule: In elimination reactions, the most substituted alkene formation is favored over the less substituted alkene.

Nucleophile from the substrate abstracts the proton from the given sulfuric acid.

Hydroxide ion is the poor leaving group where water is a good leaving group. Here sulfuric acid converted this hydroxide group to water by giving a proton.

The protonated substrate has two different beta hydrogens, which leads two substances in products.

According to Zaitsev’s rule, the most substituted alkene is favored over less substituted alkene in elimination reactions.

Therefore, 2-methylpent-2-ene is major product.

Ans:

Major product:

Minor product: