Question

On the following pages are two problems. You have a molecular formula, an IR, a ¹H NMR and a ¹³C NMR. For each
problem:
a. (1 pt) Calculate the index of hydrogen deficiency.
b. (4 pts) Propose a structure that is consistent with the spectra.
c. (1 pt) Indicate the important peaks in the IR and what features in your structure they correlate to. (Ignore the
fingerprint region.) Keep in mind that the IR can sometimes be confusing.
d. (2 pts) Label the unique protons in your structure and correlate them to the peaks in the ¹H NMR. You may not be
able to identify every peak but you should be able to identify some/most of the peaks.
e. (2 pts) Label the unique protons in your structure and correlate them to the peaks in the ¹³C NMR. You may not be
able to identify every peak but you should be able to identify some/most of the peaks.

The NMR solvent for the spectra was CDCl₃.

2) (10 pts) Below are the proton and carbon NMRs for a compound with a molecular formula of C12H14.

2) (10 pts) Below are the proton and carbon NMRs for a compound with a molecular formula of C12H14 100 1000 S D0 2 140 130 120 110 100 90 8706050 40 30 20 10 0

Answer 1

a)

H-index is 6

b)

C IR

from IR it is clear that there is a Alkyne

which indicate the peak at 2220cm-1

there is a peak at C=C region

d