You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 4-oxatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione;4-oxatricyclo[5.2.1.02,6]dec-8-en-3-one .
user
C18H18O5
assistant