You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named [(1S,2S,5R,6R,8S,9R,10S,11R,12S,13S,15R)-9,10,13,15-tetrahydroxy-6,12-dimethyl-7-oxo-17-oxapentacyclo[7.6.2.15,8.01,11.02,8]octadecan-12-yl] acetate is given. What is its corresponding molecular formula?
user
C21H30O8
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