WS8 ORGANIC 1

CHEM 205 Worksheet (WS8)

38 Points Total

Key Topics: 1H NMR, IR, and Structural Elucidation

1. (22pts) (a) Rank each proton shown below in terms of relative chemical shift in the 1H NMR spectrum.

(1 = most upfield, 3 = most downfield) (1pt for each correct ranking)

(b) For each separate compound below determine the theoretical number of peaks one would predict to see

in the 1H NMR spectra. Write the corresponding number in the empty boxes below each structure. (2pts

for each correct answer)

(c) Each of the following compounds below are characterized by a 1H NMR spectrum that consists of only

a single peak having the chemical shift indicated. Identify and draw a bond-line structure for each

compound, respectively. (4pts for each correct answer)

(i) C2H3Cl3 – at ~ 2.7 ppm (ii) C5H10 – at ~ 1.5 ppm

2. (8pts) Upon elemental analysis, a compound was found to have a 1:2:4 ratio of Oxygen to Carbon

to Hydrogen. The IR and NMR data for the compound are given below. Predict and draw the

structure responsible for this set of IR and NMR data.

3. (8pts) An aromatic amine with a molecular formula of C12H17NO gives the following IR and

NMR data. Predict and draw the structure of this compound? You can ignore the fingerprint region

and the impurity identified in this IR. The 4H multiplet (peak f and g) in the 1H NMR is two

overlapping peaks and each peak has an integration of 2H.

2H, pent.