Chapter 19, Problem 57P

Interpretation Introduction

Interpretation:

The structure for compound X is to be proposed.

Concept introduction:

DEPT stands for distortionless enhancement by polarization transfer. DEPT ${}^{13}\text{C}-\text{NMR}$ is used to indicate the number of hydrogen atoms that are bonded to each carbon while providing the information of chemical shift in a broadband proton-decoupled ${}^{13}\text{C}-\text{NMR}$ spectrum.

In a DEPT spectrum, the carbon signals are classified as ${\text{CH}}_3,{\text{CH}}_2,\text{CH\hspace{0.17em}or\hspace{0.17em}C}$ accordingly.

Presence of the electronegative substituents, like halogens or oxygen or sulfur elements, will downfield the signal, that is, the chemical shift will occur at higher δ than the unsubstituted carbons.