You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S,3aS,5R,6aR)-5-ethyl-6a-hydroxy-2,3a,5-trimethyl-6H-furo[2,3-d][1,3]dioxole-2-carbaldehyde The above is the IUPAC name of a molecule. Write its molecular formula.
user
C11H18O5
assistant