Interpretation:
Diastereomers, chemically nonequivalent sets of protons, and
Concept introduction:
Nuclear magnetic resonance (NMR) is one of the most capable analytical techniques used for determining the
When a compound containing protons or carbon-13 placed under very strong magnetic field and treated with
Nuclear magnetic resonance spectroscopy is a graph showing characteristic energy absorption frequencies and intensities of a compound under magnetic field.
When each of two hydrogens are replaced by a same group, then the compounds formed are enantiomers and the hydrogens are called enantiotopic hydrogens. Significance of enantiotopic hydrogens is that they give only one signal in
When each of two hydrogens are replaced by a same group, then the compounds formed are diastereomers and the hydrogens are called diastereotopic hydrogens. Diastereotopic hydrogens give us two different signals in
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Organic Chemistry
- (3) These natural compounds will have different numbers of 1H-NMR signals in different NMR solvents like CDC13 and methanol-d4. How many signals do you anticipate for each compound respectively in CDC13 and methanol-d4? LOCH 3 OHC. vanillin OH LOH acetoaminophen HO thymolarrow_forwardHow many signals would you expect to see in the 13C NMR spectrum of each of the following compounds? (a) Propylbenzene (b) Isopropylbenzene (c) 1,2,3-Trimethylbenzene (d) 1,2,4-Trimethylbenzene (e) 1,3,5-Trimethylbenzenearrow_forwardPredict the theoretical number of different NMR signals produced by each compound, and give approximate chemical shifts. Point out any diastereotopic relationships. (a) Ph¬CHBr¬CH2Br (b) vinyl chloridearrow_forward
- Plz do 11)(d) onlyarrow_forward) The H-NMR spectrum of compound B, C7H₁4 O, consists of the following signals: 8 0.9 (t, 6H), 1.6 (sextet, 4H), and 2.4 (t, 4H). Draw the structural formula of compound B. . You do not have to consider stereochemistry. Explicitly draw all H atoms. .arrow_forward15. A compound gives the following ¹H NMR spectrum. The signal area ratio (integration) for the three signals, observed from left to right, is 2:6:3. Which compound could this be? (A) (B) (C) (D) 3 (E) illi axi axi CI OH anote add 2 PPM 0arrow_forward
- (a) How many proton and carbon signals are expected for the 2 possible regioisomers? Clearly mark the chemically distinct/inequivalent carbons in your structures. (b) Estimate the 1H chemical shift for HB of 2-indanol and HA of 1-indanol. Is one more downfield than the other or are they expected to be similar? Explain your answer.arrow_forwardIn the 1H NMR spectra of 2-bromopropane (CH3)2CHBr and 1-bromopropane CH3CH2CH2Br, how many signals do you expect to see?arrow_forwardCompound 1 has molecular formula C7H15Cl. It shows two signals in the 1H-NMR spectrum, one at 1.08 ppm and one at 1.59 ppm. The relative integrals of these two signals are 3 and 2, respectively. Propose structures for compound 1, explaining how you reach your conclusion.arrow_forward
- The 'H NMR spectrum of compound A (C3H100) has four signals: a multiplet at 8 = 7.25-7.32 ppm (5 H), a singlet at d = 5.17 ppm (1 H), a quartet at d = 4.98 ppm (1 H), and a doublet at ô = 1.49 ppm (3 H). There are 6 signals in its 13C NMR spectrum. The IR spectrum has a broad absorption in the -3200 cm-1 region. Compound A reacts with KMNO4 in a basic solution followed by acidification to give compound B with the molecular formula C7H6O2. Draw structures for compounds A and B.arrow_forward1) They were given a mysterious chemical by ASP Rinuprasad, coded as Compound X, which was believed to be a forbidden drug smuggled through KLIA airport. Little they know about the chemical from the convict. As competent officers, together they decided to run several spectroscopic and analytical tests to determine the molecular structure of Compound X. They managed to obtain the spectra and data of IR, 'H NMR (400 MHz in CDCI 3), 13C and DEPT (100.6 MHz in CDC13), COSY, HMQC, HMBC, mass spectrometry and elemental analyses. Determine the molecular structure and name of Compound X. IR SPECTRUM 2.5 100 3.0 4.0 5,0 6.0 7.0 8.0 9.0 10 12 15 2000 avenumber cm 1500 000 1000 1Η ΝMR 7.50 7.45 7.40 7.35 7.30 7.25 7.20 7.15 7.10 7.05 7.00 55 50 1.5 100 9.5 9.0 8.5 8.0 7.5 7.0 65 60 4.5 35 3.0 2.5 20 10 0.5arrow_forward14. Compound B has molecular formula C9H12. It shows five signals in the 1H-NMR spectrum - a doublet of integral 6 at 1.22 ppm, a septet of integral 1 at 2.86 ppm, a singlet of integral 1 at 5.34 ppm, a doublet of integral 2 at 6.70 ppm, and a doublet of integral 2 at 7.03 ppm. The 13C-NMR spectrum of B shows six unique signals (23.9, 34.0, 115.7, 128.7, 148.9, and 157.4). Identify B and explain your reasoning.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning