申请人:Mueller Thomas-Norbert
公开号:US20100280276A1
公开(公告)日:2010-11-04
What is described is a process for preparing 2-hydroxyacetals of the general formula in which R
1
is hydrogen, a branched or unbranched C
1
-C
12
-alkyl radical, an electron-deficient, halogen-, NO
2
—, CN—, CF
3
—, acyl group- or branched or unbranched alkyl group-substituted or unsubstituted C
5
-C
6
-aryl or heteroaryl, and R
2
is a branched or unbranched C
1
-C
5
-alkyl radical, or both R
2
radicals are bonded directly to one another or to one another via a C
1
-C
4
unit, by reacting an enol compound of the general formula (II) in which R
3
is the same and R
1
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—R
2
(III) in which R
2
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.
所描述的是一种制备2-羟基缩醛的过程,其一般式为R1为氢,支链或非支链C1-C12烷基基团,电子不足,卤素,NO2 -,CN -,CF3 -,酰基基团或支链或非支链烷基基团取代或未取代的C5-C6芳基或杂环芳基,R2为支链或非支链C1-C5烷基基团,或两个R2基团直接结合或通过C1-C4基团结合,通过将一般式(II)的烯醇化合物与溴反应得到相应的二溴加合物,然后将此二溴加合物与一般式(III)M-O-R2(III)的烷氧化物反应,其中R2如Ia式中所定义,O为氧,M为锂,钠或钾。同样描述了通过酸性水解从获得的2-羟基缩醛制备相应的2-羟基烷醛的方法。