Mespirenona [spanish]

7alpha-Acetylthio-15beta,16beta-methylen-3-oxo-1,4-pregnadien-21,17beta-carbolacton

(17S)-7α-(Acetylthio)-15α,16α-dihydro-17-hydroxy-3-oxo-3'H-cyclopropa[15,16]pregna-1,4,15-triene-21-carboxylic acid γ-lactone

(7a,15a,16a,17a)-7-(Acetylthio)-15,16-dihydro-17-hydroxy-3-oxo-3'H-cyclopropa[15,16]pregna-1,4,15-triene-21-carboxylic Acid -Lactone