Organic Chemistry NMR

Question

III.          A proton NMR was obtained for the structure given below. Assign each peak in the spectrum to this structure.

Answer 1

The proton NMR spectrum for CH3CH2OCH3O would have the following peaks:

1. A triplet at ~1.2 ppm corresponding to the three protons on the ethyl group (CH3CH2-)
2. A singlet at ~3.4 ppm corresponding to the three protons on the methoxy group (-OCH3)
3. A singlet at ~3.8 ppm corresponding to the three protons on the second methoxy group (-OCH2-)

The presence of the two singlets at different chemical shifts indicates the presence of two different types of methoxy groups, which is consistent with the structure CH3CH2OCH3O.