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 (1S,3aR,4S,6R)-6-(3,3-dimethyloxiran-2-yl)-1,4,7-trimethyl-2,3,3a,4,5,6-hexahydro-1H-phenaleno[2,1-d][1,3]oxazole .
user
C21H27NO2
assistant