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 (4aR,7R,7aS)-7-ethoxy-4-(thiophen-3-ylmethyl)-3,4a,5,6,7,7a-hexahydro-2H-cyclopenta[b][1,4]oxazine ?
user
C14H21NO2S
assistant