1. Examples: Aldehydes and ketones

2. Conditions for Alpha Substitution
Add quickly

3. Conditions for Carbonyl Condensations

4. “Condensation” drives the overall reaction (notice equilibrium arrows)

5. Synthesis: Two products can be formed by the aldol

6. Symmetrical vs. Mixed Aldol

7. Example: Single product mixed Aldol
No acidic protons

8. Example: Single product mixed Aldol
These protons are more acidic, thus easier to remove

9. Watch out for the possibility of mixture of products
In this case no mixture… why? – stability of pdt

10. Example: Mixed Claisen
No acidic hydrogens

11. Example: Mixed Claisen-“like”
A mixed aldol – Claisen type reaction

12. Example: Intramolecular Claisen

13. Intramolecular Claisen: Application to Synthesis
The β-keto ester formed still has one acid hydrogen and thus can do additional chemistry.
Remember, the β-keto ester formed can be hydrolyzed to the β-keto acid and these can spontaneously decarboxylate.

15. Review: Synthesis of an enamine

16. Enamine’s react similar to enolates

17. Example: Stork Reaction

18. Example: Robinson Annulation

19. Biological Claisen

20. Glucose Biosynthesis (Gluconeogenesis)