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 (8-hydroxy-3,6-dimethylidene-2-oxospiro[3a,4,5,6a,7,8,9a,9b-octahydroazuleno[4,5-b]furan-9,2'-oxirane]-4-yl) 2-methylprop-2-enoate .
user
C19H22O6
assistant