Aldehid dan Keton

• Pyridoxal phosphate (PLP) is common coenzyme

• Hydrocortisone is steroid hormone secreted by adrenal glands

• Penicillin G : an antibiotic

Carbonyl Compounds

Nomenclature of Aldehydes

Naming Aldehydes and Ketones

Nomenclature of Ketones

Naming Aldehydes and Ketones

Some common names accepted by IUPAC

Boiling Points• More polar, so higher boiling point than

comparable alkane or ether.

• Cannot H-bond to each other, so lower boiling point than comparable alcohol.

Carbonyl Structure

• Carbon is sp2 hybridized.

• C=O bond is shorter, stronger, and more polar than C=C bond in alkenes.

Preparation of Aldehydes and Ketones• Aldehydes from oxidation of primary alcohols using

pyridinium chlorochromate (PCC)

• Aldehydes from reduction of carboxylic esters using diisobutylaluminum hydride (DIBAH)

Aldehydes and ketones react with nucleophiles to formaddition products: nucleophile addition reactions

Tetrahedral intermediate

Acid catalyst

All carboxylic acid derivatives react by the same generalmechanism

The tetrahedral intermediate eliminates the weakest base

Nucleophilic Addition Reactions of Aldehydes and Ketones

Nucleophilic Addition of H2O: Hydration

Aldehydes and ketones react reversibly with water to give 1,1-diols, or geminal (gem) diols

• Equilibrium favors carbonyl compound for steric reasons with the exception of formaldehyde

Formation of a New Carbon–Carbon Bond Using Grignard Reagents

Reduction by Hydride Ion

Aldehydes and ketones react with a primary amine toform an imine

This is a nucleophilic addition–elimination reactionThe pH of the reaction must be controlled

Aldehydes and ketones react with secondary amines toform enamines

Water adds to an aldehyde or ketone to form a hydrate

Addition of an Alcohol to an Aldehyde or a Ketone

Addition of Sulfur Nucleophiles

Oxidation of Aldehydes

Tollens Test

R C

O

H + 2 + 3 + 2+ 4+Ag(NH3)2+ OH

_ H2O2 Ag R C

O

O_

NH3 H2O

R C

O

H + 2 + 3 + 2+ 4+Ag(NH3)2+ OH

_ H2O2 Ag R C

O

O_

NH3 H2O

silver mirror

The reactivity of carbonyl compounds resides in thepolarity of the carbonyl group in a nucleophilic acyl substitution reaction

The -Hydrogen is Acidic

the anion is stabilized by resonance

Keto–Enol Tautomerism

The enol tautomer can be stabilized by intramolecularhydrogen bonding

One molecule of a carbonyl compound acts as a nucleophile and the other carbonyl compound acts as anelectrophile

Ketones are less susceptible than aldehydes to attack by nucleophiles

An aldol addition product loses water to form an aldol condensation product

The Mixed Aldol Addition