15. Deduce the structure of the compound (C$_7$H$_{12}$O$_3$) whose spectra properties are given below.
EIMS (m/z): 144 (M$^+$), 115 (base peak), 113, 87, 85, 59, 57 with metastable peaks at 65.9 and
63.9
$\lambda_{max}$ (EtOH): 290 nm ($\epsilon_{max}$ 22)
$\nu_{max}$(liquid film): 2980, 2860 cm$^{-1}$; 1750, 1100 cm$^{-1}$; 1710 cm$^{-1}$
$\delta_H$ (CCl$_4$): 3.65 (3H, s), 2.70 (2H, t, J = 7 Hz), 2.60 (2H, t, J = 7 Hz), 2.40 (2H, q, J = 7 Hz), 1.10
(3H, t, J = 7 Hz)
$\delta_C$ (CDCl$_3$): 210 (s), 174 (s), 50 (q), 36 (t), 37 (t), 30 (t), 10 (q)