PHA 338 - Functional Groups (Part D) L9

What is a carbonyl compound?

A compound containing a carbon-oxygen double bond (C=O), such as aldehydes, ketones, carboxylic acids, esters, and amides.

What is the structural difference between aldehydes and ketones?

Aldehydes have at least one hydrogen attached to the carbonyl carbon, while ketones have two carbon-containing groups attached to the carbonyl carbon.

Why do ketones and aldehydes have higher boiling points than alkanes of similar molecular mass?

Because ketones and aldehydes participate in dipole-dipole interactions due to the polar carbonyl group.

Why are carbonyl compounds considered hydrophilic?

The polar carbonyl group interacts with water through dipole-dipole interactions and hydrogen bonding.

How are ketones and aldehydes solvated in water?

Water molecules solvate them through dipole-dipole bonding and hydrogen bonding.

What is keto-enol tautomerism?

A reversible equilibrium between a keto form containing a carbonyl group and an enol form containing an alcohol and alkene.

What is the keto form?

The tautomer containing the carbonyl group (C=O).

What is the enol form?

The tautomer containing both an alkene and alcohol group.

Why is keto-enol tautomerism important in medicinal chemistry?

It affects molecular stability, drug activity, and receptor interactions.

What drug in the lecture demonstrates isomer-dependent biological activity?

Thalidomide.

Which thalidomide isomer is teratogenic?

The (S)-isomer.

What are phenol analogs discussed in keto-enol tautomerism?

2-pyridone and 4-pyridone systems.

What are quinolones?

Heterocyclic compounds that inhibit DNA synthesis by targeting topoisomerase II.

What is the mechanism of action of quinolones?

Inhibition of DNA synthesis through inhibition of topoisomerase II.

What functional group is present in carboxylic acids?

The carboxyl group (CO2H).

Why are carboxylic acids acidic?

Because they can donate a proton (H+) to form a resonance-stabilized carboxylate ion.

How do carboxylic acids interact with water?

Through hydrogen bonding and ion-dipole interactions.

What happens to the solubility of carboxylic acids as carbon chain length increases?

Solubility decreases as the hydrocarbon chain becomes longer.

Which short-chain carboxylic acids are completely soluble in water?

Formic acid, acetic acid, propanoic acid, and butanoic acid.

At approximately what chain length do carboxylic acids become poorly soluble?

Around 10 CH2 units.

Why do carboxylic acids contribute to soap and membrane properties?

Because they contain both a hydrophilic CO2H group and a hydrophobic hydrocarbon chain.

What drug metabolite example was shown for carboxylic acid formation?

Terfenadine metabolized into fexofenadine.

What are ion-dipole interactions?

Interactions between a charged ion and the partial charges of a dipole.

How do ketones interact with receptors?

Through ion-dipole interactions involving the carbonyl dipole.

How do esters interact with receptors?

Through ion-dipole interactions involving the ester oxygen atoms.

What is resonance in drug-receptor interactions?

A smear of electron density formed by valence electrons that affects receptor interactions.

Why are esters polar?

Because the ester functional group contains electronegative oxygen atoms creating dipoles.

How do esters interact with each other?

Through dipole-dipole interactions.

What is the most stable ester conformation discussed in lecture?

The O-R’ bond eclipsed with the C=O bond.

How are esters solvated by water?

Through dipole-dipole bonding and hydrogen bonding.

Are amides more or less reactive than esters?

Amides are less reactive than esters.

Why are amides less reactive than esters?

Because resonance delocalization stabilizes the amide bond.

Are amides polar?

Yes, amides are highly polar.

Why are amides more soluble than expected?

Because of their strong polarity and hydrogen bonding ability.

What contributes to the boiling points of amides?

Polar bonds and hydrogen bonding, especially when nitrogen has attached hydrogens.

Which is generally more polar: amides or esters?

Amides are generally more polar than esters.

What are resonance contributors in amides?

Different electron arrangements that delocalize electron density between the nitrogen and carbonyl oxygen.

What is a lactone?

A cyclic ester.

What is a lactam?

A cyclic amide.

What is the relationship between lactones and esters?

Lactones are cyclic versions of esters.

What is the relationship between lactams and amides?

Lactams are cyclic versions of amides.

What intermolecular forces are important for aldehydes and ketones?

Dipole-dipole interactions and hydrogen bonding with water.

What intermolecular forces are important for esters?

Dipole-dipole interactions and hydrogen bonding with water.

What intermolecular forces are important for amides?

Dipole-dipole interactions and strong hydrogen bonding.

Why are carbonyl-containing compounds important in medicinal chemistry?

Their polarity, resonance, and intermolecular interactions influence solubility, receptor binding, and drug activity.