You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (4R,4aR,7aR,12bS)-7,7,9-trimethoxy-3-methyl-5-[(E)-2-phenylethenyl]-1,2,4,4a,7a,13-hexahydro-4,12-methanobenzofuro[3,2-e]isoquinoline .
user
C28H31NO4
assistant