Textbook Question
How could the following compounds be prepared using an alkene as one of the starting materials?
d.
1008
views
12. Alcohols, Ethers, Epoxides and Thiols
Making Ethers - Acid-Catalyzed Alkoxylation
4:20 minutesProblem 13
Textbook Question
How could the following compound be prepared using an alkene as one of the starting materials?
Verified step by step guidance1
Analyze the target compound: The given compound is a tertiary alcohol with the structure 2,3-dimethyl-2-butanol. This indicates that the preparation involves the addition of a hydroxyl group (-OH) to a carbon atom in a highly substituted environment.
Select an appropriate alkene: To prepare this compound, the starting alkene should be 2,3-dimethyl-2-butene, as it has the same carbon skeleton as the target compound and can undergo hydration to form the alcohol.
Choose the reaction conditions: The hydration of the alkene can be achieved using acid-catalyzed hydration (e.g., H₂SO₄ and water) or oxymercuration-demercuration (using Hg(OAc)₂ and NaBH₄). These methods ensure Markovnikov addition, where the hydroxyl group attaches to the more substituted carbon.
Explain the mechanism: In acid-catalyzed hydration, the alkene undergoes protonation to form a carbocation intermediate at the more substituted carbon. Water then attacks the carbocation, followed by deprotonation to yield the alcohol. In oxymercuration-demercuration, the alkene reacts with Hg(OAc)₂ to form a mercurinium ion intermediate, which is then attacked by water. Reduction with NaBH₄ replaces the mercury group with a hydrogen atom, forming the alcohol.
Verify the product: Ensure that the reaction conditions lead to the formation of 2,3-dimethyl-2-butanol as the major product, with the hydroxyl group attached to the tertiary carbon. This matches the structure of the target compound.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
4mKey Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Alkene Reactivity
Alkenes are unsaturated hydrocarbons characterized by at least one carbon-carbon double bond. Their reactivity is primarily due to this double bond, which can undergo various reactions such as electrophilic addition, polymerization, and alkoxylation. Understanding how alkenes react is crucial for synthesizing compounds, as they can serve as versatile starting materials in organic reactions.
Recommended video:
2:09
Alkene Metathesis Concept 1
Alkoxylation
Alkoxylation is a chemical reaction where an alkene reacts with an alcohol in the presence of an acid catalyst to form an ether. This process involves the formation of a carbocation intermediate, which can then react with the alcohol to yield the ether product. Recognizing the mechanism of alkoxylation is essential for preparing ethers from alkenes, as it highlights the importance of regioselectivity and stereochemistry in the reaction.
Recommended video:
Guided course
04:25The Mechanism of Alkoxylation.
Ether Synthesis
Ethers are organic compounds characterized by an oxygen atom bonded to two alkyl or aryl groups. They can be synthesized through various methods, including the alkoxylation of alkenes, as well as through the dehydration of alcohols. Understanding the structural features and reactivity of ethers is important for predicting their behavior in chemical reactions and their applications in organic synthesis.
Recommended video:
Guided course
03:50The Mechanism of Williamson Ether Synthesis.
Related Videos
Related Practice