A compound with a molecular formula of C 10 H 12 O 2 has the following 1 H NMR spectrum. Which of the following structures is consistent with this spectrum?
SHAPE \* MERGEFORMAT

Question

A compound with a molecular formula of C 10 H 12 O 2 has the following 1 H NMR spectrum. Which of the following structures is consistent with this spectrum? 
SHAPE \* MERGEFORMAT

Quizplus · Accepted Answer

The S1U1P11 quartet at 3.7 ppm (integral 1H) indicates a phosphorus atom adjacent to a sulfur atom, with two geminal protons each coupling to the phosphorus nucleus (2JPS = 15-20 Hz). The other significant signal is the broad singlet at 11 ppm, which is consistent with an OH proton.
Looking at the structures, only structure III has a phosphorus atom adjacent to a sulfur atom, and it also has an OH group attached to a carbon adjacent to the phosphorus atom, which is consistent with the broad singlet at 11 ppm. Therefore, structure III is the best choice.

A Compound with a Molecular Formula of C10H12O2 Has the Following

A Compound with a Molecular Formula of C₁₀H₁₂O₂ Has the Following