申请人:BASF Aktiengesellschaft
公开号:US04804786A1
公开(公告)日:1989-02-14
4-Monoacetals of (E)-2-methylbut-2-ene-1,4-dial of the general formula I ##STR1## where R.sup.1 and R.sup.2 are each an aliphatic hydrocarbon radical of 1 to 12 carbon atoms, cycloalkyl of 5 to 7 carbon atoms or benzyl, or R.sup.1 and R.sup.2 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 ##STR2## where either R.sup.3 and R.sup.4 are both one of the groups ##STR3## where R.sup.1 and R.sup.2 have the above meanings, or R.sup.3 is one of the groups ##STR4## and R.sup.4 is formyl ##STR5## is reacted, at from 20.degree. to 200.degree. C., in the presence of an acidic compound, with the compound of the formula III R.sup.5 --OH (III) where R.sup.5 is hydrogen, alkyl of 1 to 12 carbon atoms or hydroxyalkyl of 2 to 5 carbon atoms, and, where R.sup.3 and R.sup.4 are each ##STR6## R.sup.5 is alkyl, and where R.sup.3 and R.sup.4 are each ##STR7## R.sup.5 is hydrogen, and where R.sup.3 is ##STR8## and R.sup.4 is ##STR9## R.sup.5 is hydrogen and/or alkyl.
通式I的(E)-2-甲基丁-2-烯-1,4-二醛的4-单缩醛具有以下结构:其中R1和R2各自是1至12个碳原子的脂肪烃基、5至7个碳原子的环烷基或苄基,或者R1和R2一起形成一个乙烯或丙烯基团,该基团可能被较低烷基取代。通过以下过程制备这些化合物:在20°C至200°C的条件下,在酸性化合物的存在下,将通式II的化合物与式III的化合物R5-OH进行反应。其中R5为氢、1至12个碳原子的烷基或2至5个碳原子的羟基烷基。当R3和R4为##STR6##时,R5为烷基;当R3和R4为##STR7##时,R5为氢;当R3为##STR8##且R4为##STR9##时,R5为氢和/或烷基。