a)
Interpretation:
A structure for ketone or aldehyde with the following descriptions is to be proposed.
C10H12O, IR: 1710 cm-1; 1HNMR: 1.01 δ (Rel.area=1.50), 2.47 δ (Rel.area=1.00), 3.66 δ (Rel.area=1.00), 7.28 δ (Rel.area=2.50).
Concept introduction:
In 1HNMR the aldehyde protons absorb near 10 δ with a coupling constant, J=3Hz. Hydrogens on the carbon next to aldehyde group absorb near 2.0-2.3 δ. Methyl ketones show a sharp three proton singlet near 2.1 δ.
To propose:
A structure for ketone or aldehyde with the following descriptions.
C10H12O, IR: 1710 cm-1; 1HNMR: 1.01 δ (Rel.area=1.50), 2.47 δ (Rel.area=1.00), 3.66 δ (Rel.area=1.00), 7.28 δ (Rel.area=2.50).
b)
Interpretation:
A structure for ketone or aldehyde with the following descriptions is to be proposed.
C6H12O3, IR: 1715 cm-1; 1HNMR: 2.18 δ (Rel.area=3.00), 2.74 δ (Rel.area=2.00), 3.37 δ (Rel.area=6.00), 4.79 δ (Rel.area=1.00).
Concept introduction:
Aldehydes and ketones show a strong absorption band in IR from 1660-1770 cm-1. Aldehydes show two characteristic C-H absorptions between 2700-2760 cm-1 and 2800-2860 cm-1. Saturated aldehydes absorb near 1730 cm-1 while aromatic aldehydes and α, β-unsaturated aldehydes absorb near 1705 cm-1. Saturated ketones and cyclohexanones absorb near 1715 cm-1 while aromatic ketones and α, β-unsaturated ketones absorb near 1685-1690 cm-1. Cyclopentanones absorb around 1750 cm-1.
In 1HNMR the aldehyde protons absorb near 10 δ with a coupling constant, J=3Hz. Hydrogens on the carbon next to aldehyde group absorb near 2.0-2.3 δ. Methyl ketones show a sharp three proton singlet near 2.1 δ.
To propose:
A structure for ketone or aldehyde with the following descriptions.
C6H12O3, IR: 1715 cm-1; 1HNMR: 2.18 δ (Rel.area=3.00), 2.74 δ (Rel.area=2.00), 3.37 δ (Rel.area=6.00), 4.79 δ (Rel.area=1.00).
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Chapter 19 Solutions
Organic Chemistry
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- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning