15-(((1,1-DIMETHYLETHYL)DIMETHYLSILYL)OXY)-16,16-DIFLUORO-9-HYDROXY-11-((TETRAHYDRO-2H-PYRAN-2-YL)OXY)PROST-5-EN-1-OIC ACID, , (5Z,9.ALPHA.,11.ALPHA.)-
15-(((1,1-dimethylethyl)dimethylsilyl)oxy)-16,16-difluoro-9-hydroxy-11-((tetrahydro-2h-pyran-2-yl)oxy)prost-5-en-1-oic acid, , (5z,9.alpha.,11.alpha.)-