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system
Name the molecular formula for the molecule established as 3,8-dimethylidene-1,4,6,9-tetraoxaspiro[4.4]nonane;3-methylidene-8-phenyl-1,4,6,9-tetraoxaspiro[4.4]nonane;3-methylidene-1,4,11-trioxaspiro[4.6]undecane using the IUPAC nomenclature.
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C28H34O11
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