| abstract |
The invention relates to a method for producing poly or monomethylol alkanoic acids of general formula (I), wherein R can be the same or different and means a substituted or unsubstituted aliphatic hydrocarbon or a methylol group, from the corresponding poly or monomethylol alkanals of general formula (II), R having the meaning given above, by oxidation with hydrogen peroxide. A differentiation is made between a starting phase and an end phase of the reaction, the reaction temperature selected during the starting phase being lower than that selected during the end phase and being at least >/= 40 DEG C to 85 DEG C, preferably 60 to 80 DEG C, especially preferably 65-75 DEG C, and the temperature during the end phase being > 85 DEG C-110 DEG C, preferably up to 105 DEG C. The method is used especially for producing dimethylol alkanoic acids from the corresponding dimethylol alkanals, especially for producing dimethylol butanal or dimethylol propanal. |