A novel intermolecular synthesis of γ-lactones via visible-light photoredox catalysis.

Direct γ-lactone formation via visible-light photoredox catalysis has been achieved efficiently including hydroxylalkylation of aromatic alkenes and transesterification. The present photocatalytic protocol has good regioselectivity and substrate compatibility, affording a novel way to intermolecular γ-lactone synthesis by the reaction of styrenes with α-bromo esters in the absence of any external oxidants.