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What is the molecular formula of the compound with this IUPAC name (3S,3aS,3'aR,4R,5'S,6aS,6'aR)-6a-(bromomethyl)-5'-[(4R)-2,2-dimethyl-1,3-dioxolan-4-yl]-2',2',3-trimethylspiro[3,3a,5,6-tetrahydro-2H-cyclopenta[b]furan-4,6'-5,6a-dihydro-3aH-furo[2,3-d][1,3]dioxole] ?
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C20H31BrO6
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