| abstract |
A process is disclosed for the preparation of 3-hydroxyalkanals having 3 to 12 carbon atoms, in particular 3 or 4 carbon atoms, by hydration of the underlying 2-alkenals with water in a homogeneous phase in the presence of an acid catalyst. The previously known hydration using mineral acids or carboxylic acids as catalyst results in low volume/time yields and/or low selectivities. These disadvantages can be avoided by using in the present invention, as catalyst, a dissolved acid-base buffer which results in a pH of from 2 to 5 in the reaction mixture; the acid component and corresponding base of which are present in a total quantity of from 0.5 to 40% by weight in the reaction mixture. The preferred buffers composed of a lower monobasic carboxylic acid and a tertiary amine can easily be recycled. |