You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3aS,4R)-4-(1,3-benzodioxol-5-yl)-5,6,7-trimethoxy-3a,4-dihydro-3H-benzo[f][2]benzofuran-1-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H20O7
assistant