You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 4-[(E)-3-(oxan-2-yloxy)-4-(trifluoromethyl)oct-1-enyl]-3,3a,4,5,6,6a-hexahydrocyclopenta[b]furan-2-one by IUPAC nomenclature, provide its molecular formula.
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C21H31F3O4
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