Grignard reagent (II), prepared from 4-tert-butylbenzyl bromide (I) and magnesium in Et2O, was condensed with estrone (III) to provide the 17-(tert-butylbenzyl)estradiol (IV). Subsequent reaction of (IV) with sulfamoyl chloride in the presence of 2,6-di-tert-butyl-4-methylpyridine (DBMP) yielded the title sulfamate ester.