You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 3-[(3aR,4R,7S,7aS)-7-benzyl-2-ethoxy-4-methyl-3,3a,5,6,7,7a-hexahydro-2H-1-benzofuran-4-yl]propanoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H32O4
assistant