| abstract |
A process for the preparation of a compound of formula (III) ##STR1## by hydrolyzing a compound of formula (I) or (II) ##STR2## wherein R 1 and R 2 , which may be the same or different, are selected from C 1-8 alkyl, C 3-8 cycloalkyl, and optionally substituted aryl, in the presence of acid at a pH above 2.0. |