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,3R,5R,6aS,7S,8S,9S,10aS)-1,3-diacetyloxy-5-hydroxy-7,8-dimethyl-7-[(2Z)-3-methylpenta-2,4-dienyl]-1,3,5,6,6a,8,9,10-octahydrobenzo[d][2]benzofuran-9-yl] butanoate .
user
C28H40O8
assistant