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 (1',7-dimethylspiro[3,5-dihydro-1,4-benzoxazepine-2,4'-piperidine]-4-yl)-[(2R)-oxolan-2-yl]methanone .
user
C20H28N2O3
assistant