Propose structures for compounds that fit the

The amount of energy required to spin-flip a nucleus depends both on the strength of the external magnetic field and on the nucleus. At a field strength of 4.7 T, rf energy of 200 MHz is required to bring a \(\mathrm {^1H}\) nucleus into resonance, but energy of only 187 MHz will bring a \(\mathrm {^{19}F}\) nucleus into resonance. Calculate the amount of energy required to spin-flip a 19F nucleus. Is this amount greater or less than that required to spin-flip a \(\mathrm {^1H}\) nucleus? Equation Transcription: Text Transcription: ^1H ^{19}F ^1H

Calculate the amount of energy required to spin-flip a proton in a spectrometer operating at 300 MHz. Does increasing the spectrometer frequency from 200 to 300 MHz increase or decrease the amount of energy necessary for resonance?

2-Chloropropene shows signals for three kinds of protons in its \(\mathrm {^1H ~NMR}\) spectrum. Explain. Equation Transcription: Text Transcription: ^1H NMR

The following \(\mathrm {^1H}\) NMR peaks were recorded on a spectrometer operating at 200 MHz. Convert each into \(\delta\) units. (a) \(\mathrm {CHCl_3;1454~ Hz}\) (b) \(\mathrm {CH_3Cl;610~ Hz}\) (c) \(\mathrm {CH_3OH;693~ Hz}\) (d) \(\mathrm {CH_2Cl_2;1060~ Hz}\) ________________ Equation Transcription: Text Transcription: ^1H delta CHCl_3;1454 Hz CH_3Cl;610 Hz CH_3OH;693 Hz CH_2Cl_2;1060 Hz

When the \(\mathrm {^1H~ NMR}\) spectrum of acetone, \(\mathrm {CH_3COCH_3}\), is recorded on an instrument operating at 200 MHz, a single sharp resonance at 2.1 \(\delta\) is seen. (a) How many hertz downfield from TMS does the acetone resonance correspond to? (b) If the \(\mathrm {^1H~ NMR}\) spectrum of acetone were recorded at 500 MHz, what would the position of the absorption be in \(\delta\) units? (c) How many hertz downfield from TMS does this 500 MHz resonance correspond to? Equation Transcription: Text Transcription: ^1H NMR CH_3COCH_3 delta ^1H NMR delta

Methyl 2,2-dimethylpropanoate \(\mathrm {(CH_3)_3CCO_2CH_3}\) has two peaks in its \(\mathrm {^1H~ NMR}\) spectrum. What are their approximate chemical shifts? Equation Transcription: Text Transcription: (CH_3)_3CCO_2CH_3 ^1H NMR

Each of the following compounds has a single \(\mathrm {^1H~ NMR}\) peak. Approximately where would you expect each compound to absorb? Equation Transcription: Text Transcription: H_3C CH_3 CH_2Cl_2 C-C H_3C N-CH_3 H_3C

Identify the different types of protons in the following molecule, and tell where you would expect each to absorb: Equation Transcription: Text Transcription: CH_3O CH_2CH_3

How many peaks would you expect in the \(\mathrm {^1H~ NMR}\) spectrum of 1,4-dimethylbenzene (para-xylene, or p-xylene)? What ratio of peak areas would you expect on integration of the spectrum? Refer to Table 13-3 for approximate chemical shifts, and sketch what the spectrum would look like. (Remember from Section 2-4 that aromatic rings have two resonance forms.) Equation Transcription: Text Transcription: CH_3 H_3C ^1H NMR

Propose a structure for a compound, \(\mathrm {C_5H_{12}O}\), that fits the following \(\mathrm {^1H~ NMR}\) data: \(0.92~ \delta\) (3 H, triplet, \(J=7~ \mathrm {Hz}\)), \(1.20~ \delta\) (6 H, singlet), \(1.50~ \delta\) (2 H, quartet, \(J=7~ \mathrm {Hz}\)), \(1.64~ \delta\) (1 H, broad singlet). Equation Transcription: Text Transcription: C_5H_{12}O ^1H NMR 0.92 delta J=7 Hz 1.20 delta 1.50 delta J=7 Hz 1.64 delta

Predict the splitting patterns you would expect for each proton in the following molecules: Equation Transcription: Text Transcription: CHBr_2CH_3 CH_3OCH_2CH_2Br ClCH_2CH_2CH_2Cl CH_3CHCOCH_2CH_3 CH_3 CH_3CH_2COCHCH_3 CH_3

Draw structures for compounds that meet the following descriptions: (a) \(\mathrm {C_2H_6O}\); one singlet (b) \(\mathrm {C_3H_7Cl}\); one doublet and one septet (c) \(\mathrm {C_4H_8Cl_2O}\); two triplets (d) \(\mathrm {C_4H_8O_2}\); one singlet, one triplet, and one quartet Equation Transcription: Text Transcription: C_2H_6O C_3H_7Cl C_4H_8Cl_2O C_4H_8O_2

The integrated \(\mathrm {^1H~ NMR}\) spectrum of a compound of formula \(\mathrm {C_4H_{10}O}\) is shown in FIGURE 13-11. Propose a structure. FIGURE 13-11 An integrated \(\mathrm {^1H~ NMR}\) spectrum for Problem 13-11. Equation Transcription: Text Transcription: ^1H NMR C_4H_{10}O ^1H NMR (delta)

Identify the indicated sets of protons as unrelated, homotopic, enantiotopic, or diastereotopic: ________________ Equation Transcription: Text Transcription: H_3C C=C H_3C CH_3 CH_3 CH_3

How many kinds of electronically nonequivalent protons are present in each of the following compounds, and thus how many NMR absorptions might you expect in each? (a) \(\mathrm {CH_3CH_2Br}\) (b) \(\mathrm {CH_3OCH_2CH(CH_3)_2}\) (c) \(\mathrm {CH_3CH_2CH_2NO_2}\) (d) Methylbenzene (e) 2-Methyl-1-butene (f) cis-3-Hexene Equation Transcription: Text Transcription: CH_3CH_2Br CH_3OCH_2CH(CH_3)_2 CH_3CH_2CH_2NO_2

How many absorptions would you expect (S)-malate, an intermediate in carbohydrate metabolism, to have in its \(\mathrm {^1H~ NMR}\) spectrum? Explain. Equation Transcription: Text Transcription: ^1H NMR

3-Bromo-1-phenyl-1-propene shows a complex NMR spectrum in which the vinylic proton at C2 is coupled with both the C1 vinylic proton \((J = \mathrm {16~ Hz})\) and the C3 methylene protons \((J = \mathrm {8~ Hz})\). Draw a tree diagram for the C2 proton signal, and account for the fact that a five-line multiplet is observed. ________________ Equation Transcription: Text Transcription: J=16 Hz J=8 Hz CH_2Br

How could you use \(\mathrm {^1H~ NMR}\) to determine the regiochemistry of electrophilic addition to alkenes? For example, does addition of HCl to 1-methylcyclohexene yield 1-chloro-1-methylcyclohexane or 1-chloro-2-methylcyclohexane? Equation Transcription: Text Transcription: ^1H NMR

At what approximate positions would you expect ethyl acrylate, \(\mathrm {H_2C=CHCO_2CH_2CH_3}\), to show \(\mathrm {^{13}C~ NMR}\) absorptions? Equation Transcription: Text Transcription: H_2C=CHCO_2CH_2CH_3 ^13C NMR

Predict the number of carbon resonance lines you would expect in the \(\mathrm {^{13}C~ NMR}\) spectra of the following compounds: Equation Transcription: Text Transcription: ^{13}C NMR H_3C C=C CH_2CH_3 H_3C CH_3

Propose structures for compounds that fit the following descriptions: (a) A hydrocarbon with seven lines in its \(\mathrm {^{13}C~ NMR}\) spectrum (b) A six-carbon compound with only five lines in its \(\mathrm {^{13}C~ NMR}\) spectrum (c) A four-carbon compound with three lines in its \(\mathrm {^{13}C~ NMR}\) spectrum Equation Transcription: Text Transcription: ^{13}C NMR ^{13}C NMR ^{13}C NMR

Classify the resonances in the \(\mathrm {^{13}C~ NMR}\) spectrum of methyl propanoate, \(\mathrm {CH_3CH_2CO_2CH_3}\) (FIGURE 13-19). FIGURE 13-19 \(\mathrm {^{13}C~ NMR}\) spectrum of methyl propanoate, Problem 13-19. ________________ Equation Transcription: Text Transcription: ^{13}C NMR CH_3CH_2CO_2CH_3 ^{13}C NMR delta

Assign a chemical shift to each carbon in 6-methyl-5-hepten-2-ol (Figure 13-20).

Estimate the chemical shift of each carbon in the following molecule. Predict which carbons will appear in the DEPT-90 spectrum, which will give positive peaks in the DEPT-135 spectrum, and which will give negative peaks in the DEPT-135 spectrum.

Propose a structure for an aromatic hydrocarbon, \(\mathrm {C_{11}H_{16}}\), that has the following \(\mathrm {^{13}C~ NMR}\) spectral data: Broadband decoupled: 29.5, 31.8, 50.2, 125.5, 127.5, 130.3, 139.8 \(\mathrm {\delta}\) DEPT-90: 125.5, 127.5, 130.3 \(\mathrm {\delta}\) DEPT-135: positive peaks at 29.5, 125.5, 127.5, 130.3 \(\mathrm {\delta}\); negative peak at 50.2 \(\mathrm {\delta}\) Equation Transcription: Text Transcription: C_{11}H_{16} ^{13}C NMR delta delta delta

We saw in Section 9-3 that addition of HBr to a terminal alkyne leads to the Markovnikov addition product, with the Br bonding to the more highly substituted carbon. How could you use \(\mathrm {^{13}C~ NMR}\) to identify the product of the addition of 1 equivalent of HBr to 1-hexyne? Equation Transcription: Text Transcription: ^{13}C NMR

Into how many peaks would you expect the \(\mathrm {^1H~ NMR}\) signals of the indicated protons to be split? (Green = Cl.) ________________ Equation Transcription: Text Transcription: ^1H NMR

How many absorptions would you expect the following compound to have in its \(\mathrm {^1H}\) and \(\mathrm {^{13}C~ NMR}\) spectra? ________________ Equation Transcription: Text Transcription: ^1H ^{13}C NMR

Sketch what you might expect the \(\mathrm {^1H}\) and \(\mathrm {^{13}C~ NMR}\) spectra of the following compound to look like (green = Cl): ________________ Equation Transcription: Text Transcription: ^1H ^{13}C NMR

How many electronically nonequivalent kinds of protons and how many kinds of carbons are present in the following compound? Don’t forget that cyclohexane rings can ring-flip.

Identify the indicated protons in the following molecules as unrelated, homotopic, enantiotopic, or diastereotopic.

The following \(\mathrm {^1H~NMR}\) absorptions were obtained on a spectrometer operating at 200 MHz and are given in hertz downield from the TMS standard. Convert the absorptions to \(\delta\) units. (a) 436 Hz (b) 956 Hz (c) 1504 Hz Equation Transcription: Text Transcription: ^1H delta

The following \(\mathrm {^1H~NMR}\) absorptions were obtained on a spectrometer operating at 300 MHz. Convert the chemical shifts from \(\delta\) units to hertz downfield from TMS. (a) 2.1 \(\delta\) (b) 3.45 \(\delta\) (c) 6.30 \(\delta\) (d) 7.70 \(\delta\) Equation Transcription: Text Transcription: ^1H NMR delta delta delta delta delta

When measured on a spectrometer operating at 200 MHz, chloroform \(\mathrm {(CHCl_3)}\) shows a single sharp absorption at 7.3 \(\delta\). (a) How many parts per million downfield from TMS does chloroform absorb? (b) How many hertz downield from TMS would chloroform absorb if the measurement were carried out on a spectrometer operating at 360 MHz? (c) What would be the position of the chloroform absorption in \(\delta\) units when measured on a 360 MHz spectrometer? Equation Transcription: Text Transcription: (CHCl_3) 7.3 delta delta

Why do you suppose accidental overlap of signals is much more common in \(\mathrm {^1H~ NMR}\) than in \(\mathrm {^{13}C~ NMR}\)? Equation Transcription: Text Transcription: ^1H NMR ^13C NMR

Is a nucleus that absorbs at 6.50 \(\delta\) more shielded or less shielded than a nucleus that absorbs at 3.20 \(\delta\)? Does the nucleus that absorbs at 6.50 \(\delta\) require a stronger applied field or a weaker applied field to come into resonance than the one that absorbs at 3.20 \(\delta\)? Equation Transcription: Text Transcription: delta delta delta delta

How many types of nonequivalent protons are present in each of the following molecules? ________________ Equation Transcription: Text Transcription: H_3C CH_3 CH_3CH_2CH_2OCH_3 C=CH_2 CO_2CH_2CH_3

The following compounds all show a single line in their \(\mathrm {^1H~NMR}\) spectra. List them in order of expected increasing chemical shift: \(\mathrm {CH_4,CH_2Cl_2}\), cyclohexane, \(\mathrm {CH_3COCH_3,H_2C=CH_2}\), benzene Equation Transcription: Text Transcription: ^1H NMR CH_4,CH_2Cl_2 CH_3COCH_3,H_2C=CH_2

How many signals would you expect each of the following molecules to have in its \(\mathrm {^1H}\) and \(\mathrm {^{13}C}\) spectra? Equation Transcription: Text Transcription: ^1H ^{13}C H_3C CH_3 C=C H_3C CH_3 CH_3 CH_3 CH_3CCH_3 H_3C CH_3C-C-OCH_3 H_3C H_3C CH_3 CH_3 CH_3

Propose structures for compounds with the following formulas that show only one peak in their \(\mathrm {^1H~ NMR}\) spectra: (a) \(\mathrm {C_5H_{12}}\) (b) \(\mathrm {C_5H_{10}}\) (c) \(\mathrm {C_4H_8O_2}\) Equation Transcription: Text Transcription: ^1H NMR C_5H_{12} C_5H_{10} C_4H_8O_2

Predict the splitting pattern for each kind of hydrogen in the following molecules: (a) \(\mathrm {(CH_3)_3CH}\) (b) \(\mathrm {CH_3CH_2CO_2CH_3}\) (c) trans-2-Butene Equation Transcription: Text Transcription: (CH_3)_3CH CH_3CH_2CO_2CH_3

Predict the splitting pattern for each kind of hydrogen in isopropyl propanoate, \(\mathrm {CH_3CH_2CO_2CH(CH_3)_2}\). Equation Transcription: Text Transcription: CH_3CH_2CO_2CH(CH_3)_2

Identify the indicated sets of protons as unrelated, homotopic, enantiotopic, or diastereotopic:

Identify the indicated sets of protons as unrelated, homotopic, enantiotopic, or diastereotopic: Equation Transcription: Text Transcription: H_3C H_3C CH_2

The acid-catalyzed dehydration of 1-methylcyclohexanol yields a mixture of two alkenes. How could you use \(\mathrm {^1H~ NMR}\) to help you decide which was which? ________________ Equation Transcription: Text Transcription: ^1H NMR CH_3 H_3O^+ CH_2 CH_3

How could you use \(\mathrm {^1H~ NMR}\) to distinguish between the following pairs of isomers? Equation Transcription: Text Transcription: ^1H NMR CH_3CH=CHCH_2CH_3 CH_2 H_2C-CHCH_2CH_3 CH_3CH_2OCH_2CH_3 CH_3OCH_2CH_2CH_3 CH_3COCH2CH_3 CH_3CH_2CCH_3 H_2C=C(CH_3)CCH_3 CH_3CH=CHCCH_3

Propose structures for compounds that it the following \(\mathrm {^1H~ NMR}\) data: (a) \(\mathrm{C_5H_{10}O}\) 0.95 \(\delta\) (6 H, doublet, \(J=7~ \mathrm {Hz}\)) 2.10 \(\delta\) (3 H, singlet) 2.43 \(\delta\) (1 H, multiplet) (b) \(\mathrm{C_3H_5Br}\) 2.32 \(\delta\) (3 H, singlet) 5.35 \(\delta\) (1 H, broad singlet) 5.54 \(\delta\) (1 H, broad singlet) ________________ Equation Transcription: Text Transcription: ^1H NMR C_5H_{10}O 0.95 delta J=7 Hz 2.10 delta 2.43 delta C_3H_5Br 2.32 delta 5.35 delta 5.54 delta

Propose structures for the two compounds whose \(\mathrm {^1H~ NMR}\) spectra are shown. Equation Transcription: Text Transcription: ^1H NMR C_4H_9Br (delta) C_4H_8Cl_2 (delta)

How many \(\mathrm {^{13}C ~NMR}\) absorptions would you expect for cis-1,3-dimethylcyclohexane? For trans-1,3-dimethylcyclohexane? Explain. Equation Transcription: Text Transcription: ^{13}C NMR

How many absorptions would you expect to observe in the \(\mathrm {^{13}C ~NMR}\) spectra of the following compounds? (a) 1,1-Dimethylcyclohexane (b) \(\mathrm {CH_3CH_2OCH_3}\) (c) tert-Butylcyclohexane (d) 3-Methyl-1-pentyne (e) cis-1,2-Dimethylcyclohexane (f) Cyclohexanone Equation Transcription: Text Transcription: ^13C NMR CH_3CH_2OCH_3

Suppose you ran a DEPT-135 spectrum for each substance in Problem 13-47. Which carbon atoms in each molecule would show positive peaks, and which would show negative peaks?

How could you use \(\mathrm {^1H}\) and \(\mathrm {^{13}C ~NMR}\) to help distinguish the following isomeric compounds of the formula \(\mathrm {C_4H_8}\)? ________________ Equation Transcription: Text Transcription: ^1H ^{13}C NMR C_4H_8 CH_2 CH_2 CH_2 CH_2 H_2C=CHCH_2CH_3 CH_3CH=CHCH_3 CH_3 CH_3C=CH_2

How could you use \(\mathrm {^1H~ NMR}\), \(\mathrm {^{13}C ~NMR}\), and IR spectroscopy to help you distinguish between the following structures? Equation Transcription: Text Transcription: ^1H NMR ^{13}C NMR CH_3

Assign as many resonances as you can to specific carbon atoms in the \(\mathrm {^{13}C ~NMR}\) spectrum of ethyl benzoate. Equation Transcription: Text Transcription: ^{13}C NMR COCH_2CH_3 delta

Assume that you have a compound with the formula \(\mathrm {C_3H_6O}\). (a) How many double bonds and/or rings does your compound contain? (b) Propose as many structures as you can that fit the molecular formula. (c) If your compound shows an infrared absorption peak at \(\mathrm {1715 ~cm^{-1}}\), what functional group does it have? (d) If your compound shows a single \(\mathrm {^{1}H ~NMR}\) absorption peak at \(2.1~ \delta\), what is its structure? ________________ Equation Transcription: Text Transcription: C_3H_6O 1715 cm^{-1} ^1H NMR 2.1 delta

The compound whose \(\mathrm {^{1}H ~NMR}\) spectrum is shown has the molecular formula \(\mathrm {C_3H_6Br_2}\). Propose a structure. ________________ Equation Transcription: Text Transcription: ^1H NMR C_3H_6Br_2 delta

The compound whose \(\mathrm {^{1}H ~NMR}\) spectrum is shown has the molecular formula \(\mathrm {C_4H_7O_2Cl}\) and has an infrared absorption peak at \(\mathrm {1740 ~cm^{-1}}\). Propose a structure. ________________ Equation Transcription: Text Transcription: ^1H NMR C_4H_7O_2Cl 1740 cm^{-1} delta

Propose structures for compounds that it the following \(\mathrm {^1H~NMR}\) data: (a) \(\mathrm {C_4H_6Cl_2}\) \(2.18~ \delta \) (3 H, singlet) \(4.16~ \delta \) (2 H, doublet, \(J=7~ \mathrm{Hz}\)) \(5.71~ \delta \) (1 H, triplet, \(J=7~ \mathrm{Hz}\)) (b) \(\mathrm {C_{10}H_{14}}\) \(1.30~ \delta\) (9 H, singlet) \(7.30~ \delta\) (5 H, singlet) (c) \(\mathrm {C_{4}H_{7}BrO}\) \(2.11~ \delta\) (3 H, singlet) \(3.52~ \delta\) (2 H, triplet, \(J=6~ \mathrm {Hz}\)) \(4.40~ \delta\) (2 H, triplet, \(J=6~ \mathrm {Hz}\)) (d) \(\mathrm {C_9H_{11}Br}\) \(2.15~ \delta \) (2 H, quintet, \(J=7~ \mathrm {Hz}\)) \(2.75~ \delta \) (2 H, triplet, \(J=7~ \mathrm {Hz}\)) \(3.38~ \delta \) (2 H, triplet, \(J=7~ \mathrm {Hz}\)) \(7.22~ \delta\) (5 H, singlet) Equation Transcription: Text Transcription: ^1H NMR C_4H_6Cl_2 2.18 delta 4.16 delta J=7 Hz 5.71 delta J=7 Hz C_{10}H{14} 1.30 delta 7.30 delta C_{4}H_{7}BrO 2.11 delta 3.52 delta J=6 Hz 4.40 delta J=6 Hz C_9H_{11}Br 2.15 delta J=7 Hz 2.75 delta J=7 Hz 3.38 delta J=7 Hz 7.22 delta

Long-range coupling between protons more than two carbon atoms apart is sometimes observed when \(\pi\) bonds intervene. An example is found in 1-methoxy-1-buten-3-yne. Not only does the acetylenic proton, \(\mathrm H_a\), couple with the vinylic proton \(\mathrm H_b\), it also couples with the vinylic proton \(\mathrm H_c\), four carbon atoms away. The data are: Construct tree diagrams that account for the observed splitting patterns of \(\mathrm H_a\), \(\mathrm H_b\), and \(\mathrm H_c\). ________________ Equation Transcription: Text Transcription: pi H_a H_b H_c H_a H_b H_c CH_3O H_a-C equiv C-C C-H_c H_b H_a(3.08 delta) H_b(4.52 delta) H_c(6.35 delta) J_a-b=3 Hz J_a-c=1 Hz J_b-c=7 Hz

The \(\mathrm {^1H}\) and \(\mathrm {^{13}C~NMR}\) spectra of compound A, \(\mathrm {C_8H_9Br}\), are shown. Propose a structure for A, and assign peaks in the spectra to your structure. Equation Transcription: Text Transcription: ^1H ^{13}C NMR C_8H_9Br delta delta

Propose structures for the three compounds whose \(\mathrm{^1H ~NMR}\) spectra are shown. Equation Transcription: Text Transcription: ^1H NMR C_5H_{10}O C_7H_7Br C_8H_9Br delta delta delta

The mass spectrum and \(\mathrm{^{13}C ~NMR}\) spectrum of a hydrocarbon are shown. Propose a structure for this hydrocarbon, and explain the spectral data. Equation Transcription: Text Transcription: ^13C NMR delta

Compound A, a hydrocarbon with \(\mathrm{M^+=96}\) in its mass spectrum, has the \(\mathrm{^{13}C}\) spectral data given below. On reaction with \(\mathrm{BH_3}\), followed by treatment with basic \(\mathrm{H_2O_2}\), A is converted into B, whose \(\mathrm{^{13}C}\) spectral data are also given below. Propose structures for A and B. Compound A Broadband-decoupled \(\mathrm{^{13}C ~NMR}\): 26.8, 28.7, 35.7, 106.9, 149.7 \(\delta\) DEPT-90: no peaks DEPT-135: no positive peaks; negative peaks at 26.8, 28.7, 35.7, 106.9 \(\delta\) Compound B Broadband-decoupled \(\mathrm{^{13}C ~NMR}\): 26.1, 26.9, 29.9, 40.5, 68.2 \(\delta\) DEPT-90: 40.5 \(\delta\) DEPT-135: positive peak at 40.5 \(\delta\); negative peaks at 26.1, 26.9, 29.9, 68.2 \(\delta\) ________________ Equation Transcription: Text Transcription: M^+=96 ^{13}C BH_3 H_2O_2 ^{13}C ^{13}C NMR delta delta ^{13}C MNR delta delta delta

Propose a structure for compound C, which has \(\mathrm{M^+=86}\) in its mass spectrum, an IR absorption at \(\mathrm{3400~ cm^{-1}}\), and the following \(\mathrm{^{13}C~ NMR}\) spectral data: Compound C Broadband-decoupled \(\mathrm{^{13}C~ NMR}\): 30.2, 31.9, 61.8, 114.7, 138.4 \(\delta \) DEPT-90: 138.4 \(\delta\) DEPT-135: positive peak at 138.4 \(\delta\); negative peaks at 30.2, 31.9, 61.8, 114.7 \(\delta\) Equation Transcription: Text Transcription: M^+=86 3400 cm^{-1} ^{13}C NMR ^{13}C NMR delta delta delta delta

Compound D is isomeric with compound C (Problem 13-61) and has the following \(\mathrm{^{13}C ~NMR}\) spectral data. Propose a structure. Compound D Broadband-decoupled \(\mathrm{^{13}C ~NMR}\): 9.7, 29.9, 74.4, 114.4, 141.4 \(\delta\) DEPT-90: 74.4, 141.4 \(\delta\) DEPT-135: positive peaks at 9.7, 74.4, 141.4 \(\delta\); negative peaks at 29.9, 114.4 \(\delta\) Equation Transcription: Text Transcription: ^13C NMR ^13C NMR delta delta delta delta

Propose a structure for compound E, \(\mathrm{C_7H_{12}O_2}\), which has the following \(\mathrm{^{13}C~ NMR}\) spectral data: Compound E Broadband-decoupled \(\mathrm{^{13}C~ NMR}\): 19.1, 28.0, 70.5, 129.0, 129.8, 165.8 \(\delta\) DEPT-90: 28.0, 129.8 \(\delta\) DEPT-135: positive peaks at 19.1, 28.0, 129.8 \(\delta\) ; negative peaks at 70.5, 129.0 \(\delta\) Equation Transcription: Text Transcription: C_7H_{12}O_2 ^13C NMR ^13C NMR delta delta delta delta

Compound F, a hydrocarbon with \(\mathrm{M^+=96}\) in its mass spectrum, undergoes reaction with HBr to yield compound G. Propose structures for F and G, whose \(\mathrm{^{13}C~ NMR}\) spectral data are given below. Compound F Broadband-decoupled \(\mathrm{^{13}C~ NMR}\): 27.6, 29.3, 32.2, 132.4 \(\delta\) DEPT-90: 132.4 \(\delta\) DEPT-135: positive peak at 132.4 \(\delta\); negative peaks at 27.6, 29.3, 32.2 \(\delta\) Compound G Broadband-decoupled \(\mathrm{^{13}C~ NMR}\): 25.1, 27.7, 39.9, 56.0 \(\delta\) DEPT-90: 56.0 \(\delta\) DEPT-135: positive peak at 56.0 \(\delta\); negative peaks at 25.1, 27.7, 39.9 \(\delta\) Equation Transcription: Text Transcription: M^+=96 ^13C NMR ^13C NMR delta delta delta delta ^13C NMR delta delta delta delta

3-Methyl-2-butanol has ive signals in its \(\mathrm{^{13}C~ NMR}\) spectrum at 17.90, 18.15, 20.00, 35.05, and 72.75 \(\delta\). Why are the two methyl groups attached to C3 nonequivalent? Making a molecular model should be helpful. Equation Transcription: Text Transcription: ^13C NMR delta H_3C CH_3CHCHCH_3

A \(\mathrm{^{13}C~ NMR}\) spectrum of commercially available 2,4-pentanediol, shows \(five\) peaks at 23.3, 23.9, 46.5, 64.8, and 68.1 \(\delta\). Explain. Equation Transcription: Text Transcription: ^13C NMR delta CH_3CHCH_2CHCH_3

Carboxylic acids \(\mathrm{(RCO_2H)}\) react with alcohols \(\mathrm{(R^\prime OH)}\) in the presence of an acid catalyst. The reaction product of propanoic acid with methanol has the following spectroscopic properties. Propose a structure. MS: \(\mathrm{M^+=88}\) IR: \(\mathrm{1735 ~cm^{-1}}\) \(\mathrm{^1H~ NMR}\): 1.11 \(\delta\) (3 H, triplet, J = 7 Hz); 2.32 \(\delta\) (2 H, quartet, J = 7 Hz); 3.65 \(\delta\) (3 H, singlet) \(\mathrm{^{13}C~ NMR}\): 9.3, 27.6, 51.4, 174.6 \(\delta\) ________________ Equation Transcription: Text Transcription: (RCO_2H) (R'OH) M^+=88 1735 cm^{-1} ^1H NMR delta delta delta ^13C NMR delta

Nitriles \((\mathrm{RC \equiv N})\) react with Grignard reagents \((\mathrm{R^\prime MgBr})\). The reaction product from 2-methylpropanenitrile with methylmagnesium bromide has the following spectroscopic properties. Propose a structure. \(\begin{aligned} &\text { MS: } \mathrm{M}^{+}=86 \\ &\text { IR: } 1715 \mathrm{~cm}^{-1} \\ &{ }^{1} \mathrm{H} \text { NMR: } 1.05~ \delta(6 \mathrm{H}, \text { doublet, } J=7 \mathrm{~Hz}) ; 2.12~ \delta(3 \mathrm{H}, \text { singlet }) ; 2.67~ \delta(1 \mathrm{H}, \text { septet, } J=7 \mathrm{~Hz}) \\ &{ }^{13} \mathrm{C} \text { NMR: } 18.2,27.2,41.6,211.2~ \delta \end{aligned}\) ________________ Equation Transcription: Text Transcription: (RC equiv N) (R'MgBr) MS:M^+=86 IR:1715 cm^-1 ^1H NMR:1.05 delta delta ^13C NMR CH_3 CH_3CHC equiv N CH_3MgBr H3_O^+

The proton NMR spectrum is shown for a compound with the formula \(\mathrm{C_5H_9NO_4}\). The infrared spectrum displays strong bands at 1750 and \(\mathrm{1562 ~cm^{-1}}\) and a medium-intensity band at \(\mathrm{1320 ~cm^{-1}}\). The normal carbon-13 and the DEPT experimental results are tabulated. Draw the structure of this compound. Equation Transcription: Text Transcription: C_5H_9NO_4 1562 cm^{-1} 1320 cm^{-1}

The proton NMR spectrum of a compound with the formula \(\mathrm{C_5H_{10}O}\) is shown. The normal carbon-13 and the DEPT experimental results are tabulated. The infrared spectrum shows a broad peak at about \(\mathrm{3340 ~cm^{-1}}\) and a medium-sized peak at about \(\mathrm{1651 ~cm^{-1}}\). Draw the structure of this compound. Equation Transcription: Text Transcription: C_5H_{10}O 3340 cm^{-1} 1651 cm^{-1} C_5H_{10}O

The proton NMR spectrum of a compound with the formula \(\mathrm{C_7H_{12}O_2}\) is shown. The infrared spectrum displays a strong band at \(\mathrm{1738 ~cm^{-1}}\) and a weak band at \(\mathrm{1689 ~cm^{-1}}\). The normal carbon-13 and the DEPT experimental results are tabulated. Draw the structure of this compound. Equation Transcription: Text Transcription: C_7H_{12}O_2 1738 cm^{-1} 1689 cm^{-1} C_7H_{12}O_2