You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-ethylbutanoyloxymethyl 2-ethoxy-3-(propanoylamino)-3,4-dihydro-1,2-benzoxaborinine-8-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H30BNO7
assistant