You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[2-[4-(17'-hydroxy-5,5,13'-trimethylspiro[1,3-dioxane-2,3'-2,4,5,6,7,8,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthrene]-11'-yl)phenyl]ethynyl]benzoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C38H44O5
assistant