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 (E)-1-(7-hydroxy-5-methoxy-2,2-dimethyl-1a,7b-dihydrooxireno[2,3-c]chromen-6-yl)-3-phenylprop-2-en-1-one .
user
C21H20O5
assistant