Alkylation of 4-hydroxybenzaldehyde (I) with 1-(2-chloroethyl)piperidine hydrochloride (II) in the presence of K2CO3 yielded (piperidinylethoxy)benzaldehyde (III), which was further reduced to the benzylic alcohol (IV) with methanolic NaBH4. Coupling of (IV) with thioacetic acid according to the Mitsunobu procedure yielded thioacetate ester (V), which was converted to the corresponding thiol (VI) by reductive cleavage of the thioester group with LiAlH4.

Elimination of the thioacetyl group of spironolactone (VII) by treatment with NaOMe yielded canrenone (VIII). The title compound was then obtained by 1,6-conjugate addition of thiol (VI) to the dienone (VIII) in the presence of metallic sodium at 60 C.