Concept explainers
(a)
Interpretation: The stable carbonyl compound,
Concept introduction: Electron withdrawing groups pulls electron density towards itself, and thus destabilizes the benzene ring, whereas electron releasing groups push electron density away from it, that is towards benzene ring, and thus stabilizes the benzene ring more.
(b)
Interpretation: The compound that forms higher percentage of hydrate at equilibrium is to be identefied.
Concept introduction:
(c)
Interpretation: The compound that exhibits carbonyl absorption at higher wavenumber in its
Concept introduction: Electron releasing groups decreases the bond order of the
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- just Barrow_forward1. Why does H2 not give an IR spectrum? 2. Explain why primary amines and unsubstituted amides have two NH stretching absorptions. 3. Why do anhydrides show two carbonyl peaks? 4. HCl is known to give addition reactions to carbon-carbon double bonds. Why is this behavior not observed in this reaction? 5. Predict the structure of the product expected from addition of molecular bromine to maleic acid.arrow_forwardHow many signals does the unsaturated ketone have in 'H NMR and 13C NMR spectra? A. five 'H signals and six 13C signals B. six 'H signals and six 1°C signals C. six 'H signals and seven 1C signals D. five 'H signals and seven 1³C signalsarrow_forward
- An unknown compound D exhibits a strong absorption in its IR spectrum at 1692 cm−1. The mass spectrum of D shows a molecular ion at m/z = 150 and a base peak at 121. The 1H NMR spectrum of D is shown below. What is the structure of D?arrow_forwardAn unknown compound D exhibits a strong absorption in its IR spectrum at 1692 cm−1. The mass spectrum of D shows a molecular ion at m/z = 150 and a base peak at 121. The 1H NMR spectrum of D is shown below. What is the structure of D?arrow_forward2. (9 points total) Each of the following Grignard reagents undergo reaction with CO₂ (solid). Grignard reagents: Number of ¹H NMR signals in the reaction product: CI A MgBr MeO B MgBr OMe MgBr Me MgCl a. (8 points) How many ¹H NMR signals do you expect to see in the spectrum of each product? Assume that the products are pure and that the carboxylic acid peak is present. Please write directly in the boxes. b. (1 point) Which Grignard reagent (A, B, C, or D) will lead to the product with the fewest ¹3C NMR signals?arrow_forward
- Answer the following questions about each of the hydroxy ketones: 1hydroxybutan-2-one (A) and 4-hydroxybutan-2-one (B).a.What is the molecular ion in the mass spectrum? b. What IR absorptions are present in the functional group region? c. How many lines are observed in the 13C NMR spectrum? d.How many signals are observed in the 1H NMR spectrum? e.Give the splitting observed for each type of proton as well as its approximate chemical shift.arrow_forwardKetones undergo a reduction when treated with sodium borohydride, NaBH4. What is the structure of the compound produced by reaction of 2-butanone with NaBH4 if it has an IR absorption at 3400 cm-1 and M+=74 in the mass spectrum?arrow_forwardAnethole, C10H12O, a major constituent of the oil of anise, has the 1H NMR spectrum shown. On oxidation with Na2Cr2O7, anethole yields p-methoxybenzoic acid. What is the structure of anethole? Assign all peaks in the NMR spectrum, and account for the observed splitting patterns.arrow_forward
- The 1H NMR spectrum of N,N-dimethylformamide shows three singlets at 2.9, 3.0, and 8.0 ppm. Explain why the two CH3 groups are not equivalent to each other, thus giving rise to two NMR signals.arrow_forwardIdentify products A and B from the given 1H NMR data. Treatment of acetone [(CH3)2C=O] with dilute aqueous base forms B. Compound B exhibits four singlets in its 1H NMR spectrum at 1.3 (6 H), 2.2 (3 H), 2.5 (2 H), and 3.8 (1H) ppm. What is the structure of B?arrow_forwardExplain why a carbonyl absorption shifts to lower frequency in an α,β-unsaturated carbonyl compound—a compound having a carbonyl group bonded directly to a carbon–carbon double bond. For example, the carbonyl absorption occurs at 1720 cm−1 for cyclohexanone, and at 1685 cm−1 for cyclohex-2-enone.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning