1. Below are shown the 1H NMR spectra of 4 isomers of C4H10O. Each isomer is alcohol
and OH proton is visible. Draw the structure which corresponds to each isomer next to
the appropriate 1H NMR spectra. Numbers are equal to integral intensity.
2. Draw structural formula of compound with summary formula C9H10 in CDCl3 (use
1D 11H NMR spectrum to find the right structure).
3. Draw structural formula of compound with summary formula C6H4NBr3 (use 1D
13C NMR spectrum to find the right structure).
4. Below is shown the 13C NMR spectrum of 2,2,4-trimethylpentane. Match the signals
to corresponding carbons in the structure.
5. Assign the individual signals of the compound (C12H15N) whose 1H NMR spectrum
(CDCl3, -10 C ) is given below. Use couplings, chemical shifts and intensities in your
analysis.
6. Completely deuterated t-butanol, (CD3)3C-OD shows 2 signals at 62 and 18 ppm in
the 13C{1 H} NMR spectrum. How many lines would you expect for the resonance at 62
ppm at room temperature?
a) 1 b) 3 c) 6 d) 9 e) 10 f) 13 g) 18 h) 19 i) 21 j) 38
7. Protons in this molecule are labeled with numbers and carbon with yellow letters in
black circles.
a) Which protons in this molecule will be exchangable in D2O solution?
a) H1 b) H6 c) H8 d) H10 e) H13 f) H1
and H8 g) H1 and H13 h) H8 and H13 i) H1, H8 and H13
j) H1 and H6
b) Which of the pairs of protons in this molecule are chemically equivalent?
a) H2 and H3 b) H4 and H5 c) H9 and H10 d) H11 and H12 e) none
of the pairs in (a)-(d) f) all of the pairs in (a)-(d)
c) Which carbon of this molecule could have a negative phase resonance at 71
ppm in the 13C DEPT-135 spectrum?
a) A b) B c) C d) D e) E f) F g) G h) J i) L j) M
8. Below is shown a part of the 13C NMR spectrum in D2O of a 10:1 mixture of two
isomers of sialic acid (A and B). Spectrum 1 is the fully 1H-decoupled. Spectrum 2 has
the decoupler turned off.
a) Which carbons of sialic acid are shown here? Mark the shifts on the structures.
b) Describe the multipicity of the signal at 177.7 ppm in the coupled spectrum (2).
c) Which is the major isomer (A or B)? _____
Give your reasoning below.