You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl (1R,2R,3R,4R,7S)-1-methyl-5-oxo-3-phenyl-7-propan-2-yl-9-oxa-6-azatricyclo[4.3.0.02,4]nonane-4-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H23NO4
assistant