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 (1S,2S,5R,6S,9R,13S,16S,18R)-16-hydroxy-2,6,13,17,17-pentamethyl-6-(4-methylpentyl)-7-oxapentacyclo[10.8.0.02,9.05,9.013,18]icos-11-en-8-one .
user
C30H48O3
assistant