/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem Q.13聽Most of the Fischer esteri... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 20: Problem (page 1038)

Q.13Most of the Fischer esterification mechanism is identical with the mechanism of acetal formation. The difference is in the final step, where a resonance-stabilized carbocation loses a proton to give the ester. Write mechanisms for the following reactions, with the comparable steps directly above and below each other. Explain why the final step of the esterification (proton loss) cannot occur in acetal formation, and show what happens instead.

Short Answer

Expert verified

Answer

In the formation of acetal from aldehyde, the loss of H+cannot take place to form carbonyl, and in the formation of ester from acid, the loss ofH+ takes place to form carbonyl.

Step by step solution

01

Step-by-Step SolutionStep 1: Fischer esterification

Fischer esterification is the conversion of carboxylic acid to ester, and this reaction takes place in the presence of a strong acid and excess alcohol.The solvent used in these reactions is methanol or ethanol.

02

Mechanism of the reaction

The major difference between these two reactions is the loss of H+. In the formation of acetal from aldehyde, the loss H+of cannot take place to form carbonyl, and in the formation of ester from acid, the loss of takes place to form carbonyl.

Mechanism of both reactions

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.

Over 30 million students worldwide already upgrade their learning with 91影视!

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

Question: Propose a mechanism for conversion of the dianion to the ketone under mildly acidic conditions.

Show how you would synthesize the following compounds, starting with acetylene and any compounds containing no more than four carbon atoms.

(a)hex-1-yne

(b)hex-2-yne

(c)cis-hex-2-ene

(d)trans-hex-2-ene

(e)1,1-dibromohexane

(f)2,2-dibromohexane

(g)pentanal, CH3CH2CH2CH2CHO

(h)pentan-2-one, CH3-CO-CH 2CH2 CH3

(i) (+/)-3,4-dibromohexane

(j)meso-butan-2,3-diol

(k)2-methylhex-3-yn-2-ol

Show how you would accomplish the following multistep syntheses. You may use any additional reagents and solvents you need.

In each case, show how you would synthesize the chloride, bromide, and iodide from the corresponding alcohol.

(a) 1-halopropane (halo = chloro, bromo, iodo)

(b)1-halo-2-methylcyclopentane

(c)1-halo-1,3-dimethylcyclohexane

(d)2-halo-1,3-dimethylcyclohexane

Question:

  1. The Key Mechanism for Fischer esterification omitted some important resonance forms of the intermediates shown in brackets. Complete the mechanism by drawing all the resonance forms of these two intermediates.
  2. Propose a mechanism for the acid-catalyzed reaction of acetic acid with ethanol to give ethyl acetate.
  3. The Principle of Microscopic Reversibility states that a forward reaction and a reverse reaction taking place under the same conditions (as in equilibrium) must follow the same reaction pathway in microscopic detail. The reverse of the Fischer esterification is the acid-catalyzed hydrolysis of an ester. Propose a mechanism for the acid-catalyzed hydrolysis of ethyl benzoate, PhCOOCH2CH3.
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Physical Chemistry

Read Explanation

Chemical Reactions

Read Explanation

Nuclear Chemistry

Read Explanation

Organic Chemistry

Read Explanation

The Earths Atmosphere

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.