You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 2-ethyl-7-hydroxy-4,5,5a,6,7,8,8a,8b-octahydro-3aH-furo[3,2-g]indol-3-one .
user
C12H19NO3
assistant