ENOLATES / ALDOL / MICHAEL

LDA

Strong bulky base that forms enolates quantitatively.

Alpha hydrogen

Hydrogen next to carbonyl is acidic because enolate is resonance stabilized.

Enolate alkylation

Enolate attacks primary alkyl halide through SN2 reaction.

SN2 trap

Tertiary aryl and vinyl halides do not work in enolate alkylation.

Br2 alpha halogenation

Adds halogen to alpha carbon of aldehydes and ketones.

HVZ reaction

PBr3 and Br2 brominate alpha carbon of carboxylic acids.

Aldol reaction

Enolate attacks another carbonyl to form beta hydroxy carbonyl.

Aldol condensation

Heating aldol product causes dehydration into alpha beta unsaturated carbonyl.

Claisen condensation

Ester enolate attacks another ester to form beta keto ester.

Dieckmann condensation

Intramolecular Claisen condensation forms ring.

Michael addition

1 4 addition to alpha beta unsaturated carbonyl.

Michael acceptor

Alpha beta unsaturated carbonyl acts as electrophile.

Robinson annulation

Michael addition followed by aldol condensation forms ring.

Acetoacetic ester synthesis

Produces alpha substituted methyl ketones.

Malonic ester synthesis

Produces alpha substituted carboxylic acids.

Decarboxylation

Heating beta keto acids removes CO2.

Iodoform reaction

I2 OH identifies methyl ketones and forms CHI3.