Process for the reduction of regioisomer where the double bond is shifted from ethylenically unsaturated alkoxylated alcohols

A process for a reduction of a content of a compound I of general formula (II)

• where R1 is hydrogen or methyl, each R2, independently from each other, is hydrogen or methyl, R3 is hydrogen or an aliphatic or cycloaliphatic or aromatic hydrocarbon with 1-8 carbon atoms, AO is a C2-C12 oxyalkylene group,
• x=0 or 1, and
• n=2-350,
• from a mixture comprising a compound I of general formula (II) and an alkoxylated alcohol A of general formula (I)
• where R1, R2, R3, AO, x, and n are as described in general formula (II) above, wherein the process comprises a treatment of the mixture comprising a compound I and an alkoxylated alcohol A with an acid, wherein the content of a compound I of general formula (II) in a mixture comprising a compound I of general formula (II) and an alkoxylated alcohol A of general formula (I) is reduced to not more than 0.5 wt. % relative to the total dry weight of the alkoxylated alcohol A of general formula (I).