You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name [(7R,8R,9E,12R)-10-methyl-5,6-dimethylidene-14-oxo-4,13-dioxatricyclo[10.2.1.03,7]pentadeca-1(15),9-dien-8-yl] 2-methylprop-2-enoate into its molecular formula.
user
C20H22O5
assistant