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 [(1R,2R,3R,12R)-10,11-diacetyl-3-hydroxy-1,5-dimethylspiro[8-oxatricyclo[7.2.1.02,7]dodec-5-ene-12,2'-oxirane]-2-yl]methyl acetate .
user
C21H28O7
assistant