Micrometers 2.5 100 9 10 7. 8 11 12 13 14 15 20 90 80 70 60 50 40 30 20 10 Compound D 4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400 Wavenumber (cm-') Compound D SH 3H 2H IH IH 10 8. O ppm Chemical shift (8) Transmittance (%) 2.

Analysis of a sweet-smelling, neutral compound of carbon, hydrogen and oxygen produced the following results: %C = 54.5; %H = 9.1. From its mass spectrum, the molecular ion had a mass/charge ratio of 88. Its infra-red spectrum showed a prominent peak at 1735 cm–1. Figure below shows the NMR spectrum of the compound. Which of the following is this compound? A. 3-hydroxybutanalB. Methyl propionateC. Ethyl acetateD. 2-methylpropanoic acidE. Methoxyacetone

Mass spectrometry of an unknown compound revealed a molecular ion at m/z 100.09. The IR spectrum, the ¹³C NMR spectrum, and the ¹H NMR spectrum are shown below. Draw the structure of this compound. 4000 220 3000 200 180 160 2000 M 1500 Wavenumbers (cm-¹) 140 120 100 1H 80 6H 1000 40 3H 20 ppm 500

Treatment of compound D with LIAIH, followed by H,O forms compound E. D shows a molecular ion in its mass spectrum at m/z = 71 and IR absorptions at 3600 –- 3200 and 2263 cm. E shows a molecular ion in its mass spectrum at m/z = 75 and IR absorptions at 3636 and 3600 – 3200 cm'. Propose structures for D and E from these data and the given 'H NMR spectra. %3D Part 1 out of 2 1Η ΝMR of D 2 H 2 H 1 H 8 7 4 3 2 1 ppm LO CO

The NMR spectra for compound 1 were acquired in a 7.5 mg / 0.6 mL solution ofCDCl3 . The 1H and 13C peaks are also listedbelow. Provide a full analysis of the NMR spectra for compound 1. correct assignment of NMR spectra of both 13C spectra.  correct rationalisation of 13C spectrum1H NMR (400 MHz, CDCl3) δ 7.73 (d, J = 9.5 Hz, 1H), 7.56 (ddd, J = 8.5, 7.5, 1.6 Hz, 1H),7.51 (dd, J = 7.5, 1.6 Hz, 1H), 7.36 (d, J = 8.5 Hz, 1H), 7.30 (dd, J = 8.5, 7.5 Hz, 1H), 6.45(d, J = 9.5 Hz, 1H).13C NMR (101 MHz, CDCl3) δ 160.79, 154.09, 143.43, 131.85, 127.87, 124.44, 118.86,116.94, 116.74.Note: There are two carbon peaks in the 13C spectrum that are so close together that they are not differentiable at the resolution in this experiment.  you should be able to assign these peaks to one of two carbon atoms in 1.

Use the 1H NMR and IR data to determine the structure of attachedcompound.

A compound displays a prominent peak at 3400 cm¹ in its IR spectrum. The mass spectrum has a molecular ion with m/z of 74. The base peak is at m/z = 45. Draw a structure that best fits this data. Drawing I Atoms and

Indicate two basic differences that exist between the spectra of 1H y 13C in NMR.

A compound displays a sharp doublet at 3400 cm-1 in its IR spectrum. The mass spectrum has a molecular ion with m/z = 115 and a base peak of m/z=72. Draw a structure that best fits this data.