You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named [(3S,3aS,5S,6aR)-5-[4-(2,3,4-trimethoxybenzoyl)piperazin-1-yl]-2,3,3a,5,6,6a-hexahydrofuro[3,2-b]furan-3-yl] nitrate is given. What is its corresponding molecular formula?
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C20H27N3O9
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