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 2-bromo-4a,10a-dihydrothianthrene;2-butan-2-yl-4a,10a-dihydrothianthrene;2-ethenyl-4a,10a-dihydrothianthrene ?
user
C42H39BrS6
assistant