Synergistic Catalysis of Se and Cu for the Activation of
<scp>
<i>α</i>
‐H
</scp>
of Methyl Ketones with Molecular Oxygen/Alcohol to Produce
<scp>
<i>α</i>
‐Keto
</scp>
Acetals
<sup>†</sup>
Selenium and copper synergistically catalyzed the oxidation/alkoxylation of methyl ketones to synthesize α‐keto acetals directly. Using O2 as oxidant and alcohol as solvent and alkoxylation reagent, the reaction is practical from industrial viewpoint. Mechanistic studies revealed that copper promoted the oxidation of organoselenium intermediates with O2 to allow the key rearrangement and selenoxide