검증된 단계별 안내
02:17
10:06
08:06A bottle of allyl bromide was found to contain a large amount of an impurity. A careful distillation separated the impurity, which has the molecular formula C3H6O. The following 13C NMR spectrum of the impurity was obtained:
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(a) Propose a structure for this impurity.
(b) Assign the peaks in the 13C NMR spectrum to the carbon atoms in the structure.
(c) Suggest how this impurity arose in the allyl bromide sample.
A laboratory student was converting cyclohexanol to cyclohexyl bromide by using one equivalent of sodium bromide in a large excess of concentrated sulfuric acid. The major product she recovered was not cyclohexyl bromide, but a compound of formula C6H10 that gave the following 13C NMR spectrum:
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(a) Propose a structure for this product.
(b) Assign the peaks in the 13C NMR spectrum to the carbon atoms in the structure.
(c) Suggest modifications in the reaction to obtain a better yield of cyclohexyl bromide.
The following proton NMR spectrum is of a compound of molecular formula C3H8O.
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(a) Propose a structure for this compound.
(b) Assign peaks to show which protons give rise to which signals in the spectrum.
Predict the approximate chemical shifts of the protons in the following compounds.
(c) CH3–O–CH2CH2CH2Cl
(d) CH3CH2–C≡C–H
Predict the multiplicity (the number of peaks as a result of splitting) and the chemical shift for each shaded proton in the following compounds.
(a)
(b)
An inexperienced graduate student was making some 4-hydroxybutanoic acid. He obtained an excellent yield of a different compound, whose 13C NMR spectrum is shown here.
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(a) Propose a structure for this product.
(b) Assign the peaks in the 13C NMR spectrum to the carbon atoms in the structure.
