Treprostinil: C~23~H~34~O~5~. Mw: 390.51. (1) Acetic acid, [[(1R,2R,3aS,9aS)-2,3,3a,4,9,9a-hexahydro-2-hydroxy-1-[(3S)-3-hydroxyoctyl]-1H-benz[f]inden-5-yl]oxy]-; (2) [(1R,2R,3aS,9aS)-2-Hydroxy-1-((3S)-3-hydroxyoctyl)-2,3,3a,4,9,9a-hexahydro-1H-cylopent[b]naphthalen-5-yl]oxy]acetate. CAS-81846-19-7 (2002).