clomegestone clomegestone clomegestone (inn), or clomagestone, also known as 6-chloro-17α-hydroxy-16α-methylpregna-4,6-diene-3,20-dione, is a steroidal progestin of the 17α-hydroxyprogesterone group that was never marketed. an acetate ester, clomegestone acetate, also exists, and similarly was never marketed. clomegestoneidentifiers iupac name (1s,2r,10r,11s,13r,14r,15s)-14-acetyl-8-chloro-14-hydroxy-2,13,15-trimethyltetracycloheptadeca-6,8-dien-5-one cas number5367-84-0pubchem cid56840824chemspider32701810uniizhw74qju5vchemical and physical dataformulac22h29clo3molar mass376.92 g·mol−13d model (jsmol)interactive image smiles cc1cc2c3c=c(c4=cc(=o)ccc4(c3ccc2(c1(c(=o)c)o)c)c)cl inchi inchi=1s/c22h29clo3/c1-12-9-17-15-11-19(23)18-10-14(25)5-7-20(18,3)16(15)6-8-21(17,4)22(12,26)13(2)24/h10-12,15-17,26h,5-9h2,1-4h3/t12-,15-,16+,17+,20-,21+,22+/m1/s1key:gqbsinxspazdsk-roxmkhfisa-n