You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-O-tert-butyl 2-O-methyl (2S,5R)-2-ethenyl-5-[(E)-3-(2-methylpropoxy)-3-oxoprop-1-enyl]pyrrolidine-1,2-dicarboxylate is the IUPAC name of a molecule. Please give its molecular formula.
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C20H31NO6
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