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 4-[(4aR,10bR)-8,9-dimethoxy-1,2,3,4,4a,10b-hexahydrophenanthridin-6-yl]-3,5-dimethyl-1,2-oxazole .
user
C20H24N2O3
assistant