1. Carbonyl Group (II) Aldehydes and Ketones Nanoplasmonic Research Group Organic Chemistry Chapter 9 Part II

2. Reactions of Aldehydes and Ketones Nucleophilic Additions Reduction and Oxidation Keto-Enol Tautomerism The Aldol Condensation

3. Reduction and Oxidation of Carbonyl Compounds Aldehydes and ketones are reduced to primary and secondary alcohols by metal hydrides Aldehydes are oxidized to carboxylic acids Aluminum alkoxide alchol Selective reduction: see equation 9.35

4. Keto-Enol Tautomerism (I) Aldehydes and ketones may exists an equilibrium mixture of two forms, the keto and enol form. Structural isomers, not contributors to a resonance hybrid A carbonyl compound must have a hydrogen atom on alpha-carbon

5. Keto-Enol Tautomerism (II) The enol form is usually unstable. This is because oxygen is more electronegative than carbon and thus forms stronger multiple bonds. Hence a carbon-oxygen double bond is more than twice as strong as a carbon- oxygen single bond, but a carbon-carbon double bond is weaker than two carbon- carbon single bonds Exceptions: Phenol, 1,3-dicarbonyl compounds due to the resonance and intermolecular hydrogen bonding

6. The Aldol Condensation (I) Organic reaction in which an enolate ion react with a carbonyl compound to form a β- hydroxyaldehyde or β-hydroxyketone, followed by dehydration to give a conjugate enone Since α-carbon acts a nucleophile, the product should be 3-hydroxy~

7. The Aldol Condensation (II) - Mechanism - α α enolate anion nucleophilean alkoxide ion aldol