You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named (3a-cyano-5-methyl-3-oxo-4,5,6,6a-tetrahydro-1H-cyclopenta[c]furan-1-yl)methyl 2-ethyl-2,4,4-trimethylpentanoate is given. What is its corresponding molecular formula?
user
C20H31NO4
assistant