SC-5233, also known as 6,7-dihydrocanrenone or 20-spirox-4-ene-3,20-dione, is a synthetic, steroidal antimineralocorticoid of the spirolactone group which was developed by G. D. Searle & Company in the 1950s but was never marketed.

[1][3] The drug was found to lack appreciable oral bioavailability and to be of low potency when administered parenterally,[4] but it nonetheless produced a mild diuretic effect in patients with congestive heart failure.

[5] Spironolactone (SC-9420; Aldactone) followed and had both good oral bioavailability and potency, and was the first synthetic antimineralocorticoid to be marketed.

[7] It is the unsubstituted parent or prototype compound of the spirolactone family of steroidal antimineralocorticoids.

[2][8] Similarly to other spirolactones like canrenone and spironolactone, SC-5233 has some antiandrogenic activity and antagonizes the effects of testosterone in animals.