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

Mechanism:

Stage 1. Formation of the radical anion

Stage 2. Dimerization

Stage 3. Elimination

Stage 4. Formation of enodiolate

Step 5. Protonation of the enodiolate

Stage 6. Tautomerism

intramolecular acyloin