You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[(2-tert-butyloxan-3-yl)methyl]-1-ethyl-3-[3-(4-hydroxypiperidin-1-yl)propyl]guanidine into its molecular formula.
user
C21H42N4O2
assistant