Acyloinic condensation transforms esters into alpha-hydroxyketones. This reaction is carried out with sodium metal in an inert solvent.

acyloionic condensation 1

Mechanism:

Stage 1. Formation of the radical anion

acyloionic condensation 2

Stage 2. Dimerization

acyloionic condensation 3

Stage 3. Elimination

acyloionic condensation 4

Stage 4. Formation of enodiolate

acyloionic condensation 5

Step 5. Protonation of the enodiolate

acyloionic condensation 6

Stage 6. Tautomerism

acyloionic condensation 7

intramolecular acyloin

acyloionic condensation 8