You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 2-[3-acetyl-7-oxo-1-(2-phenylacetyl)-4-oxa-2,6-diazabicyclo[3.2.0]heptan-6-yl]-3-methylbut-2-enoic acid .
user
C19H20N2O6
assistant