The title compound 17 has been synthesized for the use as hapten in the development of a competitive enzyme immunoassay for estrogen sulfamates. The synthesis started from estradiol diacetate 2. Oxyfunctionalization at C-11 to give 11alpha-hydroxy steroid 8 was accomplished by hydroboration/alkaline hydrogen peroxide oxidation of the 9(11)-dehydro derivative 7, which was obtained from compound 2 via 9-hydroxylation with dimethyldioxirane. After transformation of compound 8 into the allyl ether 9, the side chain was thio-functionalized at the omega-position affording the thioate 11 in two steps. Selective silylether deprotection at position 3 followed by sulfamoylation gave the sulfamate 19, which in turn was demasked at position 17 and treated with sodium borohydride/aluminum chloride to liberate the side chain thiol. Alternatively, title compound 17 was synthesized via the disulfides 13-16. For the preparation of the immunogen the title compound 17 was coupled to bovine gamma globulin in a two-step procedure using an amine and thiol specific bifunctional crosslinker. The immunization of rabbits resulted in the formation of antibodies which clearly discriminated the sulfamoylated estrogens from the non-esterified estrogens. The use of a biotinylated hapten derivative as a tracer in combination with a streptavidin-peroxidase-tetramethylbenzidine based detection system allowed the measurement of estradiol 3-sulfamate (1) in the range of about 1 to 1000 pg/well.
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