Silica gel-catalyzed air oxidation of cyclopentenones.

Cyclopentenones with an ester function at C2, an alkyl function at C3, and an ester (or alkyl) function at C4 undergo facile oxidation during silical gel column chromatography using AcOEt-hexane as the eluent to afford oxygenated products with an OH function at C2 or C4.