Question

A variety of spectra for an organic compound with molecular formula C₁₀H₁₆O are presented below. The experimental accurate mass using (+) APCI source is 153.1280 u. The 1H, 13C, COSY, HSQC and HMBC NMR spectra are given in the following slides. Propose a structure for this unknown and answer or address the following questions or requirements:

d. If there are still any questionable assignments, propose additional NMR experiments which would solve those questions and briefly explain specifically what correlations you would look for.

MASS SPECTRUM 100 ← 81 80 60 d 40 20- 91 109 152 123 ill.. ala. 0 160 120 80 m/z 40 0.0 7 2. H-NMF 6.1 ppm 6.2 6.3 6.4 6.6 6.5 6.7 6.9 6.8 7.1 7.0 ppm 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 15 1.0 0.5 ppm 2. COSY ppm 2 8 9 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 ppm 2. HSQC ppm 20 40 60 80 100 120 140 160 180 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 ppm 2. HMBC 10 40 6 60 80 100 120 140 4 160 2 180 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 45 4.0 3.5 3.0 2.5 2.0 1.5 1.0 ppm

Answer 1

Μου 153 mTH C3 CA Cg 22.34 ppm C6 33 12 fpm