12 6 Aldol Reaction and Aldol Condensation Main
- Slides: 12
12. 6 Aldol Reaction and Aldol Condensation Main Menu General reaction: 2 3 1 b-hydroxycarbonyl Aldol reaction 2 Aldol condensation a, b-unsaturateed carbonyl 1
Mechanism of Aldol Reaction E-enolate Z-enolate Aldol reaction can be reversible (retro-Aldol reaction). 2
Examples of Aldol Reaction/Condensation D -H 2 O 3
Potential Problem of Aldol Reaction Mixed aldol reaction: Desired product To avoid the formation of by-products: Add slowly 4
Use Selected Aldehydes for Aldol Reaction Aldehydes that have no a-hydrogens: formaldehyde benzaldehyde furfural pivaldehyde, trimethylacetaldehyde 2, 2 -dimethylpropanal 5
Intramolecular Aldol Reaction Formation of 5 - or 6 -membered rings. a-H 6 -membered 8 -membered Not formed 6
Intramolecular Aldol Reaction Formation of 5 - or 6 -membered rings. a-H 5 -membered a-H 7 -membered Not formed 7
Intramolecular Aldol Reaction Formation of 5 - or 6 -membered rings. a-H 5 -membered a-H 7 -membered Not formed 8
Robinson Annulation: Michael Addition Followed by Aldol Condensation Michael addition H+, heat Aldol reaction 9
Learning Check 1. What could be the product for the following reaction? 10
Learning Check 2. What could be the product for the following reaction? 3. What could be the product for the following reaction? 11
Main Menu Learning Check 4. What could be the product for the following reaction? 2 2 12