You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3'aR,10'aS)-spiro[1,3-dioxolane-2,8'-3a,4,5,6,6a,7,9,10-octahydro-1H-benzo[d][1]benzofuran]-2'-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C14H20O4
assistant