Chapter 16, Problem 16.20YT

Interpretation Introduction

Interpretation:

The normal chemical shift of a proton that is part of a fragment H-C-O in an ether or alcohol and compare to the chemical shift in Entry 3 of Table 16-5 and find the source of that difference in chemical shift.

Concept introduction:

The signal at δ = 4.2 ppm is consistent with a proton on a carbon that has an attached electronegative atom. According to the molecular formula, the electronegative atom would need to be an oxygen. The relative integration of 1 H tells us that the signal represents two protons, and the fact that the signal is split into a triplet tells us that there are two neighboring protons. As shown at the right in Table 16-5, this signal can be from a CH2 group that is bonded to O on one side and CH2 group on the other.