You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 2-[(3R,6S)-6-(4-chlorophenyl)-1-[(2R)-1-cyclopropyl-2-hydroxybutyl]-3-methyl-2-oxopiperidin-3-yl]acetic acid ?
user
C21H28ClNO4
assistant