(1R,2R,3aS,9aS)-2,3,3a,4,9,9a-hexahydro-2-(tert-butyldimethylsilyloxy)-1-((3S,1E)-3-(tert-butyldimethylsilyloxy)oct-1-enyl)-1H-cyclopenta[b]naphthalen-5-yl acetate