Question

Match the ${}^{\mathbf{13}}\mathbf{C}$NMR data to the appropriate structure.

Spectrum [1]: signals at 14, 22, 27, 34, 181 ppm

Spectrum [2]: signals at 27, 39, 186 ppm

Spectrum [3]: signals at 22, 26, 43, 180 ppm

a.

b.

c.

Short answer

Spectrum [1]: Structure B

Spectrum [2]: Structure A

Spectrum [3]: Structure C

Step-by-step solution

C13 NMR 

The compound displays a single line in the NMR spectra for each unique carbon environment; therefore, it is useful for determining the number of non-equivalent carbons.

Data and appropriate structure

The number of types of non-equivalent carbons:

A - three types of carbons

three types of carbons

B - five types of carbons

five types of carbons

C - four types of carbons

four types of carbons

Each non-equivalent carbon will have a different J value; therefore, the appropriate matches are:

1. A contains three types of carbons, so it matches with spectrum [2].

1. B contains five types of carbons, so it matches with spectrum [1].

1. C contains four types of carbons, so it matches with spectrum [3].