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 [(4S,6S,9aR)-6,9a-dimethyl-3-methylidene-2,9-dioxo-3a,4,5,6,6a,7,8,9b-octahydroazuleno[4,5-b]furan-4-yl] acetate .
user
C17H22O5
assistant