Abstract: The invention relates to a novel process for preparing 2-phenoxyacetals and the corresponding 2-phenoxycarbaldehydes. These compounds are important intermediates for the preparation of active pharmaceutical ingredients.

Abstract: What is described is a process for preparing 2-hydroxyacetals of the general formula in which R1 is hydrogen, a branched or unbranched C1-C12-alkyl radical, an electron-deficient, halogen-, NO2—, CN—, CF3—, acyl group- or branched or unbranched alkyl group-substituted or unsubstituted C5-C6-aryl or heteroaryl, and R2 is a branched or unbranched C1-C5-alkyl radical, or both R2 radicals are bonded directly to one another or to one another via a C1-C4 unit, by reacting an enol compound of the general formula (II) in which R3 is the same and R1 is as defined for formula (Ia), with bromine to give the corresponding dibromo adduct and then reacting this dibromo adduct with an alkoxide of the general formula (III) M-O—R2 (III) in which R2 is as defined for formula (Ia) and O is oxygen and M is lithium, sodium or potassium. What is likewise described is the preparation of the corresponding 2-hydroxyalkanals from the 2-hydroxyacetals thus obtained by acidic hydrolysis.