Q 62P - Organic Chemistry (Mcmurry)

Question

Compound D is isomeric with compound C (Problem 13-61) and has the following ${}^{\mathbf{13}}\mathit{C}$ NMR spectral data. Propose a structure.

Compound D Broadband-decoupled ${}^{\mathbf{13}}\mathit{C}$ NMR: 9.7, 29.9, 74.4, 114.4, 141.4 d DEPT-90: 74.4, 141.4 d DEPT-135: positive peaks at 9.7, 74.4, 141.4 d; negative peaks at 29.9, 114.4 d

Step-by-Step Solution

Answer

Structure of compound D

Step 1: C 13   NMR

Carbon-13 nuclear magnetic resonance is the technique similar to the NMR which is used to identify the carbon from the organic molecules or from the organometallic compounds like hydrogen is detected in NMR but its only sensitive to carbon-13, not carbon-12.

Step 2: Structure of compound D as per data

As per the given data the DEBT at 135 shows that the compound has two CH bonds and one $C{H}_3$ and two $C{H}_2$ carbon and the carbon has a monosubstituted double bond.

Step 3: Structure of compound D

As the absorbance of the peak at 74.4 at DEBT-90 shows, the compound has secondary alcohol, the structure must be as given:                 

                                Compound D