A compound with molecular formula $C_4{H}_6{O}_4$ produces a broad signal between $2500$ and $3600c{m}^{-1}$ in its IR spectrum and produces two signals in its ${?}^{1}H$ NMR spectrum $($a singlet at $12\mathrm{.}1ppm$ with a relative integration of $1$and a singlet at $2\mathrm{.}4ppm$ with a relative integration of $2).$ Draw the structure of the compound.