The present invention relates to compositions and methods for preparingradiopharmaceutical compounds in high chemical-purity and isotopic-purity. Thepresent invention provides polymer-bound precursors to radiopharmaceuticalcompounds that can be converted to radiopharmaceutical compounds in one step.In a preferred embodiment, a radiopharmaceutical precursor is bound to apolymeric support via a prosthetic group comprising an alkenyl-tin bond. Theradiopharmaceutical precursor is converted to a radiopharmaceutical compoundin one step involving cleavage of the alkenyl-tin bond and incorporation of aradioisotope to form the radiopharmaceutical compound. Importantly, thepolymeric support containing the toxic tin by-products can be easily removedfrom the radiopharmaceutical compound by filtration. The present invention canbe used to install a large number of different radioisotopes. In a preferredembodiment, the radioisotope is 211At, 123I, or 131I.
