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 (2S,5S)-17-benzyl-5-(hydroxymethyl)-2-(2-methylpropyl)-1,4,8-triazacyclooctadecane-3,7,18-trione .
user
C27H43N3O4
assistant