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What is the molecular formula of the compound with this IUPAC name methyl (3aR,5Z,9E,13E,15aS)-10,14-dimethyl-3-methylidene-2-oxo-3a,4,7,8,11,12,15,15a-octahydrocyclotetradeca[b]furan-6-carboxylate ?
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C21H28O4
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