You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name tert-butyl 2-[(1-methylimidazol-2-yl)methyl-prop-2-enoylamino]-6-azaspiro[2.5]octane-6-carboxylate ?
user
C20H30N4O3
assistant