MedChem L11

What are carbonyl carbon linked to

3 atoms only

Geometry around carbonyl carbon

Trigonal planar

Bond angles in carbonyl carbon

120

Polarity of C=O group

Polar

What does the nucleophilic addition of O / N nucleophiles work for

Rxn works with aldehydes and ketone

Which is more reactive aldehyde or ketone

aldehyde

Why are aldehydes more reactive

Steric and electronic reasons

Steric reasons why aldehydes are more reactive

Reduction in bond angle

Substituents more closer together in products v reagents

Steric hinderance in ketones disfavours addition rxn

Acid catalysis

Increases electrophilicity of carbonyl group

Base catalysis

Increases nucleophilicity of alcohol group

Hemiacetal

Has 1 ether and 1 alcohol functional group

Step 1 in hemiacetal formation

Protonation of the carbonyl carbon

Step 2 in hemiacetal formation

Nucleophilic addition of alcohol

Step 3 in hemiacetal formation

Formation of hemiacetal and regeneration of catalyst

When are hemiacetals converted to acetals

In the presence of alcohol

Nucleophilic addition of amines

addition reaction followed by elimination rxn

What is an addition reaction followed by elimination rxn

Condensation reaction

If r = alkyl or aryl substituents

Reagent = amine

Product = imine

If r = OH

Reagent = hydroxyl amine

Product = oxide

If R = NHR

Reagent = hydrazine

Product = hydrazone