Visible Light Photoredox-Catalyzed Formyl/Carboxylation of Activated Alkenes with Glyoxylic Acid Acetals and CO 2 .

A photoredox-catalyzed sequential α-formyl/carboxylation of alkenes with glyoxylic acid acetals and CO 2 has been developed to afford a range of masked γ-formyl esters in good yields, which could be readily transformed into diverse compounds, such as γ-formyl ester, hemiacetal, and 1,4-diol. This reaction features mild conditions, readily available starting materials, and operational simplicity.