You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (3aR,4R,7S,7aS)-2-(2-bromo-4-nitrophenyl)-7-methyl-4,7a-dihydro-3aH-4,7-epoxyisoindole-1,3-dione .
user
C15H11BrN2O5
assistant