Question

Propose a reasonable structure based on the molecular formula, the^1H NMR, and the proton-decoupled^13C NMR data below. The unknown compound has a molecular formula of C_7H_16O_2.

Answer 1

Here the molecular formula is C7H1602. From the C-NMR spectrum we can see atoms (Since the molecule contains 7 carbon atoms) From the H-NMR spectrum, the signal around 0.7 ppm (6H) is due to two similar methyl groups attached to -CH2 group. The signal around 1.3 ppm (4H) is due to two ry carbon atom. Also there is a pair of three equivalent carbon similar -CH2 groups attached to -CH3 group. The signal around 2.8 ppm (2H) is due to two similar protons attached to an electronegative element. The signal around 3.5 ppm (4H) is due to two similar -CH2 groups attached to an electronegative element. Therefore, the structure of the compound must be, CH3 CH2 H2 H2 CH2 CH3

Answer 2

7.9 C7H1602 23.1 number of double bonds0 он .740.9 88.7 HO C13 estimation 23.1 7.9 70 60 50 40 30 20 10 PPM

0.83 4.24 он 1.69 3.39 H1 estimation 3.39 HO 4.24 1.89 0.83 PPM