You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (4S)-4-(2-methylpropyl)-1'-(2-phenoxyacetyl)spiro[2-oxa-5-azabicyclo[11.4.0]heptadeca-1(17),13,15-triene-7,4'-piperidine]-6-one into molecular formula.
user
C31H42N2O4
assistant