You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by methyl 2-[(2R,3S)-1-(4-methoxyphenyl)-4-oxo-3-[(1R)-1-phenylmethoxyethyl]azetidin-2-yl]acetate ?
user
C22H25NO5
assistant