You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 5-[(3aR,4R,5R,6aR)-5-hydroxy-4-[(3S)-3-hydroxyoct-1-enyl]-1,1-dioxo-3,3a,4,5,6,6a-hexahydro-2H-cyclopenta[b]thiophen-2-yl]pentanoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H36O6S
assistant