Aldehid dan Keton Pyridoxal phosphate PLP is common

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 sp 2 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 form addition products: nucleophile addition reactions Tetrahedral intermediate Acid catalyst

All carboxylic acid derivatives react by the same general mechanism The tetrahedral intermediate eliminates the weakest base

Nucleophilic Addition Reactions of Aldehydes and Ketones

Nucleophilic Addition of H 2 O: 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 to form an imine This is a nucleophilic addition–elimination reaction The p. H of the reaction must be controlled

Aldehydes and ketones react with secondary amines to form 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 silver mirror

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

The a-Hydrogen is Acidic the anion is stabilized by resonance

Keto–Enol Tautomerism The enol tautomer can be stabilized by intramolecular hydrogen bonding

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

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