Enols and enolates a substitutions and condensations of ketones and aldehydes
This presentation is the property of its rightful owner.
Sponsored Links
1 / 41

Enols and Enolates a Substitutions and Condensations of Ketones and Aldehydes PowerPoint PPT Presentation


  • 77 Views
  • Uploaded on
  • Presentation posted in: General

Enols and Enolates a Substitutions and Condensations of Ketones and Aldehydes. Tautomerization Accelerated in Acid. a -Halogenation. Reaction Occurs via Enol. Tautomerization Acceleration in Base. Alkylation in Base Reaction with 1 o RX. Using LDA as Base to form Enolate.

Download Presentation

Enols and Enolates a Substitutions and Condensations of Ketones and Aldehydes

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Enols and enolates a substitutions and condensations of ketones and aldehydes

Enols and Enolatesa Substitutions and Condensations of Ketones and Aldehydes


Tautomerization accelerated in acid

Tautomerization Accelerated in Acid


A halogenation

a-Halogenation


Reaction occurs via enol

Reaction Occurs via Enol


Tautomerization acceleration in base

Tautomerization Acceleration in Base


Alkylation in base reaction with 1 o rx

Alkylation in BaseReaction with 1o RX


Using lda as base to form enolate

Using LDA as Base to form Enolate


Alkylation a to c o c alkylation preferred

Alkylation a to C=OC-alkylation preferred


Alkylation occurs on less hindered side of c o

Alkylation Occurs on Less Hindered Side of C=O


Malonic ester synthesis of carboxylic acids

Malonic Ester Synthesis of Carboxylic Acids


H s are unusually acidic

H’s are unusually acidic


Decarboxylation loss of co 2

Decarboxylation (loss of CO2)


2 acidic a h s 2 alkylations determine the product of the synthesis

2 Acidic a H’s, 2 Alkylations; Determine the Product of the Synthesis


All b keto acids are unstable and decarboxylate

All b-keto acids are unstable and Decarboxylate


Enamines can be alkylated

Enamines can be Alkylated


Alkylation of an enamine a position is activated

Alkylation of an Enaminea Position is Activated


Complements lda reaction

Complements LDA Reaction


Lda vs enamine reaction

LDA vs. Enamine Reaction


A selenation formation of a b unsaturated ketones

a-Selenation: Formation of a,b-Unsaturated Ketones


Mechanism

Mechanism


Synthesis

Synthesis


Aldol condensation

Aldol Condensation


Enolate undergoes nucleophilic addition

Enolate Undergoes Nucleophilic Addition


Aldol condensation dimerization of 3 pentanone

Aldol CondensationDimerization of 3-Pentanone


Crossed aldol between 2 different c o compounds

Crossed Aldol Between 2 Different C=O Compounds


Four possible condensation products

Four Possible Condensation Products


Crossed aldol condensation

Crossed Aldol Condensation


Dehydration of aldol products

Dehydration of Aldol Products


Predicting aldol dehydration products

Predicting Aldol Dehydration Products


Intramolecular aldol

Intramolecular Aldol


Predict the product

Predict the Product


Conjugate addition

Conjugate Addition


1 2 vs 1 4 addition

1,2 - vs. 1,4 - Addition


Michael addition conjugate addition of enolate to a b unsaturated ketone

Michael AdditionConjugate Addition of Enolate to a,b-Unsaturated Ketone


Robinson annulation michael addition followed by aldol consensation

Robinson Annulation:Michael Addition followed by Aldol Consensation


  • Login