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 (4R,4aR,12bS)-4,6,6-trideuterio-9-methoxy-3-methyl-1,2,4a,5,7a,13-hexahydro-4,12-methanobenzofuro[3,2-e]isoquinolin-7-one .
user
C18H21NO3
assistant