Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 10: Problem 123

Treatment of alcolols with strong acidl leads to dehydration, which is elimination of water from adjacent rarbon atoms to give an alkene. \- Zaitsev's rule is folloved, that is, the predominant product is the most stable (usually the most highly substituted) alkene. The mechanism is the reverse of acid catalyzed hydration of an alkene.

Short Answer

Expert verified
Question: Using Zaitsev's rule, predict the major alkene product of an alcohol dehydration reaction of 3-methyl-2-butanol with a strong acid. Answer: The major alkene product formed in the dehydration reaction of 3-methyl-2-butanol with a strong acid will be 2-methyl-2-butene. This is the more stable, highly substituted alkene product as per Zaitsev's rule.

Step by step solution

01

Identify the alcohol and the strong acid

First, identify the alcohol molecule that will undergo dehydration and the strong acid being used in the reaction. The alcohol will have a hydroxyl group (-OH), and the strong acid will have a hydrogen ion (H+) that can protonate the alcohol.
02

Assess the substitution pattern of the alcohol

Determine the substitution pattern of the alcohol, which means counting how many carbon atoms are attached to the carbon atom bearing the hydroxyl group. The substitution patterns are primary (1°, one carbon atom), secondary (2°, two carbon atoms), or tertiary (3°, three carbon atoms). This information will be crucial to predict which product will be the most stable according to Zaitsev's rule.
03

Protonate the alcohol

The reaction begins with the protonation of the alcohol by the strong acid, resulting in an oxonium ion and a water molecule. In this step, the hydroxyl group (-OH) of the alcohol gains a hydrogen ion (H+) from the strong acid to form a water molecule (H2O) and a positively charged oxonium ion (R2C-OH2+).
04

Formation of carbocation

The water molecule acts as a leaving group, leaving behind a positively charged carbocation intermediate. The carbocation formed will depend on the substitution pattern of the alcohol. In some cases, carbocation rearrangement can occur via hydride or alkyl shifts to form a more stable carbocation if necessary.
05

Elimination of a proton

The final step involves the elimination of a proton adjacent to the carbocation by a base (usually the conjugate base of the strong acid). This elimination leads to the formation of an alkene, with a double bond between the formerly carbocation-bearing carbon atom and the adjacent carbon atom from which the proton was removed.
06

Apply Zaitsev's rule

Apply Zaitsev's rule to determine the predominant product by identifying the most stable (most highly substituted) alkene formed in the reaction. The more substituted the alkene, the more stable it is. For example, a more substituted alkene will have more adjacent carbon atoms and fewer adjacent hydrogen atoms.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Thiols are named in the same manner as aleohols, but the suffix e of the parent alkane is retained and thiol added. \- In compounds containing other functional groups of higher precedence, the presence of \(-\$ M\) is indicated by the prefix werapto.

Compoends that contain an \(\mathrm{N}-\mathrm{H}\) group associate by hydrogen bonding- (a) Do you expect this associabion to be stronger or weaker than that of coupoxinds containing an \(\mathrm{O}-\mathrm{H}\) group? (b) Based on your answer to part (a), which would you predict to have the higher boiling point, 1-butanol or 1-butanamuine?

Sinmilarly, thiols are stronger acids than alcohols. Compare, for example, the p \(K\). values of ethanol and ethanethiol in dilute aquecous solution.

Draw the product of treating each alcohol with \(\mathrm{PCC}\). (a) M-Mexanol (b) 2.Mexanol (c) Cyclohexanol

Draw structural formulas for the alkenes formed on acid-catalyzed dehydration of each alcohol. Where isomeric alkenes are prossible, predict which alkene is the major product. (a) 3.Methyl-butanol (racemic) (b) 2 Methylcyclopentanol (racemic)
See all solutions

Recommended explanations on Chemistry Textbooks

Kinetics

Read Explanation

The Earths Atmosphere

Read Explanation

Inorganic Chemistry

Read Explanation

Chemical Analysis

Read Explanation

Chemistry Branches

Read Explanation

Physical Chemistry

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free