You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(1R,2S,3R,4S,4aS,5R,8aR)-1-acetyloxy-4-[(1S)-1-acetyloxy-2-(5-oxo-2H-furan-3-yl)ethyl]-3,5-dihydroxy-3,4,8a-trimethyl-8-methylidene-1,2,4a,5,6,7-hexahydronaphthalen-2-yl] 2-methylpropanoate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C28H40O10
assistant