Synthesis of 3,5‐Dialkoxy‐1,2‐dioxolanes by Alkoxyperoxidation of 1,3‐Diketones with Hydrogen Peroxide and Alcohols

A three‐component reaction of 1,3‐diketones with H₂O₂ and alcohols was discovered. 3,5‐Dialkoxy‐1,2‐dioxolanes are formed in yield ranging from 13% to 83% using an excess of acids such as H₂SO₄, MeHSO₃, p‐TsOH·H₂O or BF₃·Et₂O. This reaction proceeds with the formation of 3,5‐dialkoxy‐1,2‐dioxolanes despite the diversity of possible reaction pathways leading to different types of peroxides, oligomers, polymers or hydrolysis. 3,5‐Dimethoxy‐1,2‐dioxolanes exhibit high activity against phytopathogenic fungi.