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Enols and Enolates a Substitutions and Condensations of Ketones and Aldehydes

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.

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Enols and Enolates a Substitutions and Condensations of Ketones and Aldehydes

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  1. Enols and Enolatesa Substitutions and Condensations of Ketones and Aldehydes

  2. Tautomerization Accelerated in Acid

  3. a-Halogenation

  4. Reaction Occurs via Enol

  5. Tautomerization Acceleration in Base

  6. Alkylation in BaseReaction with 1o RX

  7. Using LDA as Base to form Enolate

  8. Alkylation a to C=OC-alkylation preferred

  9. Alkylation Occurs on Less Hindered Side of C=O

  10. Malonic Ester Synthesis of Carboxylic Acids

  11. H’s are unusually acidic

  12. Decarboxylation (loss of CO2)

  13. 2 Acidic a H’s, 2 Alkylations; Determine the Product of the Synthesis

  14. All b-keto acids are unstable and Decarboxylate

  15. Enamines can be Alkylated

  16. Alkylation of an Enaminea Position is Activated

  17. Complements LDA Reaction

  18. LDA vs. Enamine Reaction

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

  20. Mechanism

  21. Synthesis

  22. Aldol Condensation

  23. Enolate Undergoes Nucleophilic Addition

  24. Aldol CondensationDimerization of 3-Pentanone

  25. Crossed Aldol Between 2 Different C=O Compounds

  26. Four Possible Condensation Products

  27. Crossed Aldol Condensation

  28. Dehydration of Aldol Products

  29. Predicting Aldol Dehydration Products

  30. Intramolecular Aldol

  31. Predict the Product

  32. Conjugate Addition

  33. 1,2 - vs. 1,4 - Addition

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

  35. Robinson Annulation:Michael Addition followed by Aldol Consensation

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