You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-[(6R,7R)-2-bromo-6-methoxy-5,5-dimethyl-6,7-dihydrothieno[3,2-b]pyran-7-yl]piperidin-2-one by IUPAC nomenclature, provide its molecular formula.
user
C15H20BrNO3S
assistant