Patent ID: 7342054

Claim:
A process for preparing a compound of formula I where R 1 is H or CH 3 A is (CH 2 ) where m has the values of 0 or 1, R 2-6 are the same or different and are OH, H, aliphatic or aromatic hydrocarbon, n has the values of 0, 1 or 2, comprising reacting a compound of the formula II where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , A, m and n are each as defined above and R 7 and R 8 may be the same or different and are methyl, ethyl or propyl, with water in amounts wherein the ratio of compound (II) to water is between 1:1 and 1:3 over an acidic ion exchanger in a fixed bed, and the resulting compound III R 7 R 8 C═O (III) is removed continuously from the reaction medium, and wherein no dried air is blown into the reaction medium to remove water or compound (III) therefrom, and wherein compound III is removed by reduction in pressure.