You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 2-O-tert-butyl 3-O-methyl (1S,3S)-1-prop-2-enyl-2-azaspiro[4.4]nonane-2,3-dicarboxylate .
user
C18H29NO4
assistant