| 摘要 |
4-Monoacetals of (E)-2-methylbut-2-ene-1,4-dial of the general formula I <IMAGE> (I) where R1 and R2 are each an aliphatic hydrocarbon radical of 1 to 12 carbon atoms, cycloalkyl of 5 to 7 carbon atoms or benzyl, or R1 and R2 together form an ethylene or propylene radical which may furthermore be substituted by lower alkyl, are prepared by a process in which a compound of the general formula II <IMAGE> (II) where either R3 and R4 are both one of the groups <IMAGE> where R1 and R2 have the above meanings, or R3 is one of the groups <IMAGE> and R4 is formyl <IMAGE> is reacted, at from 20 DEG to 200 DEG C., in the presence of an acidic compound, with the compound of the formula III R5-OH (III) where R5 is hydrogen, alkyl of 1 to 12 carbon atoms or hydroxyalkyl of 2 to 5 carbon atoms, and, where R3 and R4 are each <IMAGE> R5 is alkyl, and where R3 and R4 are each <IMAGE> R5 is hydrogen, and where R3 is <IMAGE> and R4 is <IMAGE> R5 is hydrogen and/or alkyl.
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