(1'S,7'aR)-1'-[(S)-(1,5-dimethylhexyl)]-1',2',6',7'-tetrahydrospiro[1,3-dioxolane-2,5'-[5'H]indene]-7'a(3'H)-carboxylic acid (R)-tetrahydro-4,4-dimethyl-2-oxo-3-furanyl ester