You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by (5R,9S)-5-hydroxy-9-(4-methoxyphenyl)-6-methyl-5-prop-2-enyl-8-oxatetracyclo[8.8.0.02,6.011,16]octadeca-10,15-dien-14-one ?
user
C28H34O4
assistant