Preparation of sulfate esters. the synthesis of steroid sulfates by a dicyclohexylcarbodiimide-mediated sulfation

Abstract

Steroid sulfates were synthesized in good yield under mild conditions by a dicyclohexylcarbodiimide-mediated sulfation. The reaction is especially suitable for the synthesis of 35-labeled steroid sulfates owing to the readily available and reasonably priced 35SO 4 =. Alkyl hydroxyl groups can be sulfated under dilute reaction conditions while phenolic hydroxyl groups are not sulfated, as illustrated in the direct synthesis of 17β-estradiol-17-sulfate from 17β-estradiol. Phenolic hydroxyl groups, however, can be sulfated under concentrated reaction conditions. There is no noticeable alteration in the position of the double bonds or sulfonation of the aromatic rings. The yields of steroid sulfate seem to be partially dependent upon the type and position of the hydroxyl group being sulfated. The more sterically hindered the alkyl hydroxyl group the lower the yield.