Chemical Properties
White Solid
Uses
Cyproterone is used to control sexual attraction in men in cases of sexual deviations, as
well as for inoperable prostate gland carcinoma. In women, it is used for severe cases of
androgenization, and in children with idiopathic premature sexual maturity.
Uses
An antiandrogen, suppresses Testosterone and its metabolites. Derivatives of Cyproterone are administered to patients suffering from hypersexuality and to help facilitate the sexual transformation of male-to-female transsexuals.
Definition
ChEBI: Cyproterone is a 20-oxo steroid, a 17alpha-hydroxy steroid, a chlorinated steroid, a 3-oxo-Delta(4) steroid and a tertiary alpha-hydroxy ketone. It has a role as an androgen antagonist. It derives from a hydride of a pregnane.
World Health Organization (WHO)
Cyproterone was introduced in the late sixties. It is an orallyactive
anti-androgen with competitive inhibitory effects on androgen-sensitive
target organs. It also has anti-gonadotropic and progestative properties. In 1995
the drug was found to have a hepatotoxic effect.
Synthesis
Cyproterone, 6-chloro-17|á-hydroxy-1|á,2|á-methylenpregna-4,6-dien-3,20-
dione acetate (29.2.14), is made from 17|á-hydroxyprogesterone acetate (28.3.36).
Dehydrating this using chloranyl (tetrachloro-p-benzoquinone) results in formation of an
additional double bond at position C6¨CC7 (29.2.8), and subsequent dehydration using selenium dioxide to form the corresponding divinyl ketone, 17|á-acetoxy-1,4,6-pregnatrien-
3,20-dione (29.2.9). Reacting this with diazomethane results in a 1,3-dipolar addition
reaction at C1¨CC2 of the double bond of the steroid system, which forms a derivative of
dihydropyrazole (29.2.10). This compound cleaves when reacted with chloric acid, releasing nitrogen molecules and forming a cyclopropane derivative (29.1.11). Next, the double
bond at C6¨CC7 is selectively oxidized by benzoyl peroxide, and the resulting epoxide
(29.2.12) undergoes a reaction with hydrochloric acid in acetic acid, resulting in the formation of chlorine and its subsequent dehydration, and a simultaneous opening of the cyclopropane ring, forming the compound (29.2.13). Heating this in collidine results in
intramolecular alkylation, causing cyclization into a cyclopropane ring, which forms cyproterone (29.2.14).
