You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-7-chloro-4,6-dimethoxy-2-(4-methylfuran-2-yl)-2-propan-2-yl-1-benzofuran-3-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H19ClO5
assistant