| abstract |
The present invention relates to a method for preparing derivatives of water soluble polymers bearing a terminal carboxylic acid or ester thereof. The method involves hydrolyzing an ortho ester of a water soluble polymer, to provide the corresponding acid. In addition, the invention provides water soluble polymers that carry a terminal carboxylic acid or ester thereof, intermediates and reagents used to carry out the method, as well as gels, pharmaceutical formulations, conjugates related to the water soluble polymer derivatives described. . |