You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as (2S)-2-hydroxy-3-methyl-N-[(2S)-1-[[(5S)-7-methyl-6-oxo-5,7,8,9-tetrahydrobenzo[7]annulen-5-yl]amino]-1-oxopropan-2-yl]butanamide using the IUPAC nomenclature.
user
C20H28N2O4
assistant