ABSTRACT
The analysis of the EI-MS provides the m/z of the molecular ion (180) and some recognizable fragmentations, such as M-30 (typically loss of formaldehyde, m/z 150), M-43, and M-57. However, although an aliphatic ketone might fit some of the above fragmentations, there is no evidence of carbonyl carbons in the13C NMR spectrum. Besides, it shows four aromatic or alkene carbons, two of which are very deshielded (152.8 and 154.3 ppm) probably due to the effect of directly bound oxygen atoms. Since there are only four signals in this region, a symmetrically disubstituted benzene, a 5-membered heteroaromatic ring, or even a diene could be proposed. However, the intensity of the signals at 114.8 and 115.9 ppm suggest that each of them correspond to a pair of chemically equivalent CH, so a disubstituted benzene is the most plausible option. Apart from these signals, four aliphatic carbons with high chemical shifts (45–70 ppm) are observed, thus evidencing that they also suffer the deshielding effect of the aromatic ring and/or the oxygen atoms of the molecule.
