Chapter 14, Problem 14.31P

A compound of molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{8}}{\text{O}}_{\text{2}}$ shows no IR peaks at $3600-320{\text{0 or 1700 cm}}^{-1}$. It exhibits one singlet in its ${}^{\text{1}}\text{H}$ NMR spectrum at $3.6\text{9 ppm}$, and one line in its ${}^{\text{13}}\text{C}$ NMR spectrum at $67\text{ ppm}$. What is the structure of this unknown?