Radioiododestannylation: preparation and evaluation of radioiodinated thienyl alcohols.

Radioiododestannylations was employed to prepare a series of four specifically labeled thienyl alcohols: 1-(5-iodo-2-thienyl)-cyclopentan-1-ol and -cyclohexan-1-ol; 17 alpha-(5-iodo-2-thienyl)-17 beta-estradiol and -estradiol-3-O-methyl ether. The method utilized 5-(trimethylstannyl)thienyl intermediates which had been prepared in good yields from 2,5-bis(trimethylstannyl)thiophene and the appropriate cyclic ketones. The trimethylstannyl substrates reacted with no-carrier-added Na125I in the presence of 30% H2O2-acetic acid (2:1) at pH 4.5 at ambient temperature for 5-15 min to give, after HPLC separation, the desired 5-[125I]iodothien-2-yl products in greater than 90% isolated yields. Although tissue distribution studies in rats were uneventful, the methodology employed to give the labeled products possesses distinct advantages compared to alternative methods for preparing radioiodinated aryl moieties.