You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (5S,6R,11S,12R)-12-[tert-butyl(dimethyl)silyl]oxy-11-(3-hydroxypropyl)-4,7-dioxadispiro[4.0.46.45]tetradecan-11-ol by IUPAC nomenclature, provide its molecular formula.
user
C21H40O5Si
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