You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule N-[7-[(3,4-dihydroxy-5-methoxy-6-methyl-3,4-dihydro-2H-pyran-2-yl)oxy]-8-methoxy-2-oxochromen-3-yl]prop-2-ynamide ?
user
C20H19NO9
assistant