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 [(3S,9R)-3-methoxy-5-oxo-11-phenyl-2,6,10,12-tetraoxatricyclo[7.4.0.03,7]tridecan-8-yl] acetate .
user
C18H20O8
assistant