tigestol tigestol tigestol (inn, usan), also known as 17α-ethynylestr-5(10)-en-17β-ol, is a steroidal progestin of the 19-nortestosterone group that was developed by organon in the 1960s but was never marketed. it is an isomer of the related 19-nortestosterone derivative progestins lynestrenol and cingestol. tigestolidentifiers iupac name (8r,9s,13s,14s,17r)-17-ethynyl-13-methyl-2,3,4,6,7,8,9,11,12,14,15,16-dodecahydro-1h-cyclopentaphenanthren-17-ol cas number896-71-9pubchem cid13471chemspider12892unii1wae0p123gkeggd06145chemblchembl2105440chemical and physical dataformulac20h28omolar mass284.443 g·mol−13d model (jsmol)interactive image smiles cc12ccc3c(c1ccc2(c#c)o)ccc4=c3cccc4 inchi inchi=inchi=1s/c20h28o/c1-3-20(21)13-11-18-17-9-8-14-6-4-5-7-15(14)16(17)10-12-19(18,20)2/h1,16-18,21h,4-13h2,2h3/t16-,17-,18+,19+,20+/m1/s1key:dhokbghaeuvrmo-slhncblasa-n