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1 Million+ Step-by-step solutionsmath books Q:Calculate to three significant figures the amount of energy absorbedCalculate to three significant figures the amount of energy absorbed by a hydrogen when it undergoes an (-to-( spin flip in the field of
(a) A 2.11-T magnet (v = 90 MHz);
(b) An 11.75-T magnet {v = 500 MHz)?
Q:For each of the following changes, indicate whether it correspondsFor each of the following changes, indicate whether it corresponds to moving to the right or the left in an NMR spectrum,
(a) Increasing radio frequency (at constant magnetic field strength);
(b) Increasing magnetic field strength (at constant radio frequency: moving “upfield”; Section 10-4):
(c) Increasing chemical shift;
(d) Increased shielding.
Q:Sketch a hypothetical low-resolution NMR spectrum showing the positions ofSketch a hypothetical low-resolution NMR spectrum showing the positions of the resonance peaks for all magnetic nuclei for each of the following molecules. Assume an external magnetic field of 2.11 T. How would the spectra change if the magnetic field were 8.46 T?
(a) CFC13 (Freon 11)
(b) CH3CFC12 (HCFC-141b)
(c)
Sketch a hypothetical low-resolution NMR spectrum showing the positions ofQ:If the NMR spectra of the molecules in Problem 30If the NMR spectra of the molecules in Problem 30 were recorded by using high resolution for each nucleus, what differences would be observed?
Q:The 1H NMR spectrum of CH3COCH2C(CH3)3, 4,4-dimethyl-2-pentanone, taken at 300The 1H NMR spectrum of CH3COCH2C(CH3)3, 4,4-dimethyl-2-pentanone, taken at 300 MHz shows signals at the following positions: 307, 617, and 683 Hz downfield from tetramethylsilane
(a) What are the chemical shifts (() of these signals?
(b) What would their positions be in hertz, relative to tetramethylsilane, if the spectrum were recorded at 90 MHz? At 500 MHz?
(c) Assign each signal to a set of hydrogens in the molecule.
Q:Order the 1H NMR signals of the following compounds byOrder the 1H NMR signals of the following compounds by chemical-shift position (lowest to highest). Which one is the most upheld? The most downfield?
(a) H3C-CH3
(b) H2C==CH2
(c) H3C-O-CH3
(d)
Order the 1H NMR signals of the following compounds by

(e)

Order the 1H NMR signals of the following compounds by

(f)

Order the 1H NMR signals of the following compounds byQ:Which hydrogens in the following molecules exhibit the more downfieldWhich hydrogens in the following molecules exhibit the more downfield signal relative to (CH3)4 Si in the NMR experiment? Explain.
(a) (CH3)2O or (CH3)3N
(b)
Which hydrogens in the following molecules exhibit the more downfield

(c)

Which hydrogens in the following molecules exhibit the more downfield

(d) (CH3)2S or (CH3)2S==O

Q:How many signals would be present in the 1H NMRHow many signals would be present in the 1H NMR spectrum of each of the cyclopropane derivatives shown below? Consider carefully the geometric environments around each hydrogen.
(a)
How many signals would be present in the 1H NMR

(b)

How many signals would be present in the 1H NMR

(c)

How many signals would be present in the 1H NMR

(d)

How many signals would be present in the 1H NMR

(e)

How many signals would be present in the 1H NMRQ:1H NMR spectra for two haloalkanes are shown below. Propose1H NMR spectra for two haloalkanes are shown below. Propose structures for these compounds that are consistent with the spectra.
(a) C5H11C1, spectrum A;
1H NMR spectra for two haloalkanes are shown below. Propose

(b) C4H8Br2, spectrum B.

1H NMR spectra for two haloalkanes are shown below. ProposeQ:The following 1H NMR signals are for three molecules withThe following 1H NMR signals are for three molecules with ether functional groups. All the signals are singlets (single, sharp peaks). Propose structures for these compounds,
(a) C3H8O2, ( = 3.3 and 4.4 ppm (ratio 3:1);
(b) C4H10O3, ( = 3.3 and 4.9 ppm (ratio 9:1);
(c) C5H12O2, ( = 1.2 and 3.1 ppm (ratio 1:1).
Compare and contrast these spectra with that of 1,2-dimethoxyethane.
Q:(a) The 1H NMR spectrum of a ketone with the(a) The 1H NMR spectrum of a ketone with the molecular formula C6Hl2O has ( = 1.2 and 2.1 ppm (ratio 3:1). Propose a structure for this molecule.
(b) Each of two isomeric molecules related to the ketone in (a) has the molecular formula C6H12O2. Their 1H NMR spectra are described as follows: isomer 1, ( = 1.5 and 2.0 ppm (ratio 3:1); isomer 2, ( = 1.2 and 3.6 ppm (ratio 3:1). All signals in these spectra are singlets. Propose structures for these compounds. To what compound class do they belong?
Q:List the four important features of 1H NMR and theList the four important features of 1H NMR and the information you can derive from them.
Q:Describe in which ways the 1H NMR spectra of theDescribe in which ways the 1H NMR spectra of the compounds below would be similar and how they would differ. Address each of the four issues you listed in Problem 41. To which compound class does each of these compounds belong?
Describe in which ways the 1H NMR spectra of theQ:Below are shown three C4H8C12 isomers on the left andBelow are shown three C4H8C12 isomers on the left and three sets of 1H NMR data that one would expect on application of the simple N + 1 rule on the right. Match the structures to the proper spectral data.
(i) ( = 1.5 (d, 6 H) and 4.1 (q, 2 H) ppm
(ii) ( = 1.6 (d, 3 H), 2.1 (q, 2 H), 3.6 (t, 2 H), and 4.2 (sex, 1 H) ppm
(iii) ( = 1.0 (t, 3 H), 1.9 (quin, 2 H), 3.6 (d, 2 H), and 3.9 (quin, 1 H) ppm
(a)
Below are shown three C4H8C12 isomers on the left and

(b)

Below are shown three C4H8C12 isomers on the left and

(c)

Below are shown three C4H8C12 isomers on the left andQ:The 1H NMR chemical shifts are given for each ofThe 1H NMR chemical shifts are given for each of the following compounds.-As best you can, assign each signal to the proper group of hydrogens in the molecule and sketch a spectrum for each compound, incorporating spin-spin splitting whenever appropriate,
(a) CI2CHCH2CI, 5 4.0 and 5.8 ppm;
(b) CH3CHBrCH2CH3, 8 1.0, 1.7, 1.8, and 4.1 ppm;
(c) CH3CH2CH2COOCH3, 8 1.0. 1.7. 2.3, and 3.6 ppm;
(d) C1CH2CHOHCH3, 8 1.2, 3.0, 3.4, and 3.9 ppm.
Q:A hydrocarbon with the formula C6H14 gives rise to ‘HA hydrocarbon with the formula C6H14 gives rise to ‘H NMR spectrum G (margin). What is its structure? This molecule has a structural feature similar to that of another compound whose spectrum is illustrated in this chapter. What molecule is that? Explain the similarities and differences in the spectra of the two.
Q:Treatment of the alcohol corresponding to NMR spectrum D inTreatment of the alcohol corresponding to NMR spectrum D in Problem 47 with hot concentrated HBr yields a substance with the formula C5H11Br. Its 1H NMR spectrum exhibits signals at ( = 1.0 (t, 3 H), 1.2 (s, 6 H), and 1.6 (q. 2 H) ppm. Explain.
Q:The 1H NMR spectrum of 1-chloropentane is shown at 60The 1H NMR spectrum of 1-chloropentane is shown at 60 MHz (spectrum H) and 500 MHz (spectrum I), Explain the differences in appearance of the two spectra, and assign the signals to specific hydrogens in the molecule.
The 1H NMR spectrum of 1-chloropentane is shown at 60The 1H NMR spectrum of 1-chloropentane is shown at 60The 1H NMR spectrum of 1-chloropentane is shown at 60Q:Propose a reasonable structure for each of the following moleculesPropose a reasonable structure for each of the following molecules on the basis of the given molecular formula and of the 1H and proton-decoupled l3C NMR data
(a) C7H16O, spectra J and K (* = CH2 by DEPT);
(b) C7H16O, spectra L and M (the assignments in M were made by DEPT).
Propose a reasonable structure for each of the following moleculesPropose a reasonable structure for each of the following moleculesQ:The 1H NMR spectrum of cholesteryl benzoate is shown asThe 1H NMR spectrum of cholesteryl benzoate is shown as spectrum N. Although complex, il contains a number of distinguishing features. Analyze the absorptions marked by integrated values. The inset is an expansion of the signal at ( = 4.85 ppm and exhibits an approximately first-order splitting pattern. How would you describe this pattern?
The 1H NMR spectrum of cholesteryl benzoate is shown asThe 1H NMR spectrum of cholesteryl benzoate is shown asQ:The tcrpcne a-terpineol has the molecular formula C10H18O and isThe tcrpcne a-terpineol has the molecular formula C10H18O and is a constituent of pine oil. As the -ol ending in the name suggests, it is an alcohol. Use its 1H NMR spectrum (spectrum O, p. 443) to deduce as much as you can about the structure of a-terpineol.
Q:Study of the solvolysis of derivatives of menthol [5-methyl 2Study of the solvolysis of derivatives of menthol [5-methyl 2 (I methylethyl) cyclohexanol] has greatly enhanced our understanding of these types of reactions. Heating the isomer of the 4-methylbenzenesulfonate ester shown below in 2, 2, 2-trifluoro-ethanol (a highly ionizing solvent of low nucleophilicity) leads to two products with the molecular formula C10H18.
(a) The major product displays 10 different signals in its l3C NMR spectrum. Two of them are at relatively low field, about ( ~ 120 and 145 ppm, respectively, The 1H NMR spectrum exhibits a multiplet near 5 = 5 ppm (1 H); all other signals are upheld of ( = 3 ppm. Identify this compound.
(b) The minor product gives only seven l3C signals. Again, two are at low field (8 ~ 125 and 140 ppm), but, in contrast with the 1H NMR data on the major isomer, there are no signals at lower field than ( = 3 ppm. Identify this product and explain its formation mechanistically.
(c) When the solvolysis is carried out starting with the ester labeled with deuterium at C2, the ‘H spectrum of the resulting major product isomer in (a) reveals a significant reduction of the intensity of the signal at 8 = 5 ppm, a result indicating the partial incorporation of deuterium at the position associated with this peak. How might this result be explained?
Q:The molecule (CH3)4Si (tetramethylsilane) is used as an internal standardThe molecule (CH3)4Si (tetramethylsilane) is used as an internal standard in 1H NMR spectroscopy. One of the following properties makes it especially useful. Which one?
(a) Highly paramagnetic
(b) Highly colored
(c) Highly volatile
(d) Highly nucleophilic
Q:One of the following compounds will show a doublet asOne of the following compounds will show a doublet as part of its ‘H NMR spectrum. Which one?
(a) CH4
(b) ClCH(CH3)2
(c) CH3CH2CH3
(d)
One of the following compounds will show a doublet asQ:In the1’H NMR spectrum of 1-fluorobutane, the most deshielded hydrogensIn the1’H NMR spectrum of 1-fluorobutane, the most deshielded hydrogens are those bound to
(a) C4
(b) C3
(c) C2
(d) C1
Q:One of the following compounds will have one peak inOne of the following compounds will have one peak in its ‘H NMR spectrum and two peaks in its l3C NMR spectrum. Which one?
(a)
One of the following compounds will have one peak in

(b)

One of the following compounds will have one peak in

(c) CH3–CH3
(d)

One of the following compounds will have one peak in

(e)

One of the following compounds will have one peak inQ:Draw the structures of the molecules with the following names. (a)Draw the structures of the molecules with the following names.
(a) 4,4-Dichloro-trans-2-octene
(b) (Z)-4-bromo-2-iodo-2-pentene
(c) 5-Methyl.cis-3-hexen-l-ol
(d) (R)-l,3-Dichlorocycloheptene
(e) (E)-3-Methoxy-2-methyl-2-buten-l-ol
Q:Name each of the following molecules in accord with theName each of the following molecules in accord with the IUPAC system of nomenclature.
a.
Name each of the following molecules in accord with the

b.

Name each of the following molecules in accord with the

c.

Name each of the following molecules in accord with the

d.

Name each of the following molecules in accord with the

e.

Name each of the following molecules in accord with the

f.

Name each of the following molecules in accord with the

g.

Name each of the following molecules in accord with the

h.

Name each of the following molecules in accord with the

i.

Name each of the following molecules in accord with theQ:Name each of the compounds below. Use cis / transName each of the compounds below. Use cis / trans and/or E/Z designations, if appropriate, to designate stereochemistry
a.
Name each of the compounds below. Use cis / trans

b.

Name each of the compounds below. Use cis / trans

c.

Name each of the compounds below. Use cis / transQ:Of each pair of the following compounds, which one shouldOf each pair of the following compounds, which one should have the higher dipole moment the higher boiling point?
(a) cis- or trans-1,2-Difluoroethene;
(b) Z- or E-1,2-difluoropropene:
(c) Z- or £-2,3-difluoro-2-butene
Q:Draw the structures of each of the following compounds, rankDraw the structures of each of the following compounds, rank them in order of acidity, and circle the most acidic hydrogen(s) in each: cyclopentane, cyclopentanol, cyclopentene, 3-cyclopenten-l-ol.
Q:Assign structures to the following molecules on the basis ofAssign structures to the following molecules on the basis of the indicated ‘H NMR spectra A-E Consider stereochemistry, where applicable
(a) C4H7C1, NMR spectrum A;
(b) C5H8O2, NMR spectrum B;
(c) C4H8O, NMR spectrum C;
(d) Another C4H8O, NMR spectrum D
(e) C3H4C12, NMR spectrum E
Assign structures to the following molecules on the basis ofAssign structures to the following molecules on the basis ofAssign structures to the following molecules on the basis ofAssign structures to the following molecules on the basis ofAssign structures to the following molecules on the basis ofQ:Explain the splitting patterns in 1HNMR spectrum D in detail.Explain the splitting patterns in 1HNMR spectrum D in detail. The insets are fivefold expansions
Q:For each of the pairs of alkenes below, indicate whetherFor each of the pairs of alkenes below, indicate whether measurements of polarity alone would be sufficient to distinguish the compounds from one another. Where possible, predict which compound would be more polar?
a.
For each of the pairs of alkenes below, indicate whether

b.

For each of the pairs of alkenes below, indicate whether

c.

For each of the pairs of alkenes below, indicate whetherQ:Place the alkenes in each group in order of increasingPlace the alkenes in each group in order of increasing stability of the double bond and increasing heat of hydrogenation.
a.
Place the alkenes in each group in order of increasing

b.

Place the alkenes in each group in order of increasing

c.

Place the alkenes in each group in order of increasing

d.

Place the alkenes in each group in order of increasing

e.

Place the alkenes in each group in order of increasingQ:Write the structures of as many simple alkenes as youWrite the structures of as many simple alkenes as you can that, upon catalytic hydrogenation with H2 over Pt. will give as the product
(a) 2-methylbutane:
(b) 2.3-dimethylbutane;
(c) 3.3-dimethylpentane;
(d) 1, 1, 4-trimethylcyclohexane.
In each case in which you have identified more than one alkene as an answer, rank the alkenes in order of stability.
Q:The reaction between 2-bromobutane and sodium ethoxide in ethanol givesThe reaction between 2-bromobutane and sodium ethoxide in ethanol gives rise to three E2 products. What are they? Predict their relative amounts.
Q:What key structural feature distinguishes haloalkanes that give more thanWhat key structural feature distinguishes haloalkanes that give more than one stereoisomer on E2 elimination from those that give only a single isomer exclusively?
Q:Write the most likely major product(s) of each of theWrite the most likely major product(s) of each of the following haloalkanes with sodium ethoxide in ethanol or potassium tert-butoxide in 2-methyl-2-propanol (tert-butyl alcohol),
(a) Chloromethane;
(b) 1-bromopentane;
(c) 2-bromopentane;
(d) 1-chloro-l-methylcyclohexane;
(e) (l-bromoethyl)-cyclopentane
(f) (2R, 3R)-2-chloro-3-ethylhexane;
(g) (2R, 3S)-2-chloro-3-ethylhexane;
(h) (2S.3R)-2-chloro-3-ethylhexane.
Q:Referring to the data in Chapter Integration Problem 11-27 predictReferring to the data in Chapter Integration Problem 11-27 predict how the rate of E2 reaction between 1-bromopropane and sodium ethoxide in ethanol would compare with those of the three substrates discussed in that problem under the same reaction conditions.
Q:Draw Newman projections of the four stereo-isomers of 2-bromo-3-methylpentane inDraw Newman projections of the four stereo-isomers of 2-bromo-3-methylpentane in the conformation required for E2 elimination. Are the reactive conformations also the most stable conformations? Explain.
Q:Referring to the answer to Problem 38 of Chapter 7,Referring to the answer to Problem 38 of Chapter 7, predict (qualitatively) the relative amounts of isomeric alkenes that are formed in the elimination reactions shown.
Q:Referring to the answers to Problem 30 of Chapter 9,Referring to the answers to Problem 30 of Chapter 9, predict (qualitatively) the relative yields of all the alkenes formed in each reaction
Q:Compare and contrast the major products of dehydrohalogenation of 2-chloro-4-methylpentaneCompare and contrast the major products of dehydrohalogenation of 2-chloro-4-methylpentane with
(a) Sodium ethoxide in ethanol and
(b) Potassium tert-butoxide in 2-methyl-2-propanol (tert-butyl alcohol).
Write the mechanism of each process. Next consider the reaction of 4-methyl-2-pentanol with concentrated H2S04 at 130°C and compare its product(s) and the mechanism of its (their) formation with those from the de-hydro-halogenations in (a) and (b).
Q:Referring to Problem 59 of Chapter 7, write the structureReferring to Problem 59 of Chapter 7, write the structure of the alkene that you would expect to be formed as the major product from E2 elimination of each of the chlorinated steroids shown.
Q:1-Methylcyclohexene is more stable than methylene-cyclohexane (A, in the margin),1-Methylcyclohexene is more stable than methylene-cyclohexane (A, in the margin), but methylene-cyclopropane (B) is more stable than 1-methyl-cyclopropene. Explain.
Q:Give the products of bimolecular elimination from each of theGive the products of bimolecular elimination from each of the following isomeric halogenated compounds.
a.
Give the products of bimolecular elimination from each of the

b.

Give the products of bimolecular elimination from each of the

One of these compounds undergoes elimination 50 times faster than the other. Which compound is it? Why?

Q:Explain in detail the differences between the mechanisms giving riseExplain in detail the differences between the mechanisms giving rise to the following two experimental results.
Explain in detail the differences between the mechanisms giving riseExplain in detail the differences between the mechanisms giving riseQ:The molecular formulas and 13C NMR data (in ppm) forThe molecular formulas and 13C NMR data (in ppm) for several compounds are given here. The type of carbon, as revealed from DEPT spectra, is specified in each case. Deduce a structure for each compound,
(a) C4H6: 30.2 (CH2), 136.0 (CH);
(b) C4H6O: 18.2 (CH3). 134.9 (CH), 153.7 (CH), 193.4 (CH3);
(c) C4H8: 13.6 (CH3), 25.8 (CH2), 112.1 (CH2), 139.0 (CH);
(d) C5H10O: 17.6 (CH3), 25.4(CH3), 58.8 (CH2), 125.7 (CH), 133.7 (Cquatemary);
(e) C5H8: 15.8 (CH2), 31.1 (CH2), 103.9 (CH2), 149.2 (Cqualemary);
(f) C7H10: 25.2 (CH2), 41.9 (CH), 48.5 (CH2), 135.2 (CH).
Q:Data from both ordinary and DEPT l3C NMR spectra forData from both ordinary and DEPT l3C NMR spectra for several compounds with the formula C5H10 are given here. Deduce a structure for each compound,
(a) 25.3 (CH2);
(b) 13.3 (CH3), 17.1 (CH3), 25.5 (CH3), 118.7 (CH), 131.7 (Cqualernaiy)
(c) 12.0 (CH3), 13.8 (CH3), 20.3 (CH2), 122.8 (CH), 132.4 (CH).
Q:From the Hooke’s law equation, would you expect the C-XFrom the Hooke’s law equation, would you expect the C-X bonds of common haloalkanes (X = Cl, Br, 1) to have IR bands at higher or lower wave numbers than are typical for bonds between carbon and lighter elements (e.g., oxygen)?
Q:Convert each of the following IR frequencies into micrometers. (a) 1720Convert each of the following IR frequencies into micrometers.
(a) 1720 cm-1 (C=0)
(b) 1650 cm-1 (C=C)
(c) 3300 cm-1 (O-H)
(d) 890 cm-1 (alkene bend)
(e) 1100 cm-1 (C-O)
(f) 2260 cm-1 (C=N)
Q:Match each of the following structures with the IR dataMatch each of the following structures with the IR data that correspond best. Abbreviations: w. weak; m, medium: s, strong; br, broad,
(a) 905 (s), 995 (m), 1040 (m), 1640 (m), 2850-2980 (s), 3090 (m), 3400 (s, br) cm-1;
(b) 2840 (s), 2930 (s) cm-1;
(c) 1665 (m), 2890-2990 (s), 3030 (m) cm-1;
(d) 1040 (m), 2810-2930 (s), 3300 (s, br) cm-1.
Match each of the following structures with the IR dataQ:An organic compound exhibits IR spectrum F. From the groupAn organic compound exhibits IR spectrum F. From the group of structures below, choose one that matches the spectrum best.
An organic compound exhibits IR spectrum F. From the groupAn organic compound exhibits IR spectrum F. From the groupQ:The three compounds hexane. 2-methylpentane and 3-methylpentane correspond to theThe three compounds hexane. 2-methylpentane and 3-methylpentane correspond to the three mass spectra shown below. Match each compound with the spectrum that best fits its structure on the basis of the fragmentation pattern
The three compounds hexane. 2-methylpentane and 3-methylpentane correspond to theThe three compounds hexane. 2-methylpentane and 3-methylpentane correspond to theThe three compounds hexane. 2-methylpentane and 3-methylpentane correspond to theQ:Assign as many peaks as you can in the massAssign as many peaks as you can in the mass spectrum of 1-bromopropane (Figure 11-24).
Q:The following table lists selected mass-spectral data for three isomericThe following table lists selected mass-spectral data for three isomeric alcohols with the formula C5H12O. On the basis of the peak positions and intensities, suggest structures for each of the three isomers. A dash means that the peak is very weak or absent entirely.
The following table lists selected mass-spectral data for three isomericQ:Calculate the degree of un-saturation that corresponds to each ofCalculate the degree of un-saturation that corresponds to each of the following molecular formulas,
(a) C7H12
(b) C8H7NO2;
(c) C6C16;
(d) C10H22O11
(e) C6H10S;
(f) C18H28O2
Q:A hydrocarbon with an exact molecular mass of 96.0940 exhibitsA hydrocarbon with an exact molecular mass of 96.0940 exhibits the following spectroscopic data: 1H NMR δ = 1.3 (m, 2 H), 1.7 (m, 4 H), 2.2 (m, 4 H), and 4.8 (quin, J = 3 Hz, 2 H) ppm; l3C NMR 8 = 26.8, 28.7, 35.7, 106.9, and 149.7 ppm. The IR spectrum is shown below (spectrum G). Hydrogenation furnishes a product with an exact molecular mass of 98.1096. Suggest a structure for the compound consistent with these data.
A hydrocarbon with an exact molecular mass of 96.0940 exhibitsQ:The isolation of a novel form of molecular carbon C60The isolation of a novel form of molecular carbon C60 was reported in 1990. The substance has the shape of a soccer ball of carbon atoms and possesses the nickname “buckyball” (you don’t want to know the IUPAC name). Hydrogenation produces a hydrocarbon with the molecular formula C60H36. What is the degree of un-saturation in C60? In C60H36 does the hydrogenation| result place limits on the numbers of π bonds and rings in “buckyball”? (More on CW) is found in Chemical Highlight 15-1.)
Q:You have just been named president of the famous perfumeYou have just been named president of the famous perfume company. Scents “R” Us Searching for a hot new item to market, you run across a bottle labeled only C10lH26O, which contains a liquid with a wonderfully sweet rose aroma. You want more, so you set out to elucidate its structure. Do so from the following data, (i) 1H NMR: clear signals at δ = 0.94 (d, J = 7 Hz. 3 H), 1.63 (s, 3 H). 1.71 (s, 3 H), 3.68 (t, J = 7 Hz. 2 H). 5.10 (t. J = 6 Hz, 1 H) ppm: the other 8 H have overlapping absorptions in the range δ = 1.3-2.2 ppm. (ii) l3C NMR (1H decoupled): δ = 60.7. 125.0. 130.9 ppm: seven other signals are upheld of δ = 40 ppm. (iii) IR: v = 1640 and 3350 cm-1, (iv) Oxidation with buffered PCC (Section 8-6) gives a compound with the molecular formula C10H18O. Its spectra show the following changes compared with the starting material: 1H NMR: signal at δ = 3.68 ppm is gone, but a new signal is seen at δ = 9.64 ppm: 13C NMR: signal at δ = 60.7 ppm is gone, replaced by one at δ = 202.1 ppm; IR: loss of signal at v = 3350 cm-1; new peak at v = 1728 cm” (v) Hydrogenation gives C10H22O, identical with that formed on hydrogenation of the natural product geraniol (see margin).
Q:Using the information in Table 11-4 match up each setUsing the information in Table 11-4 match up each set of the following IR signals with one of these naturally occurring compounds, camphor, menthol, chrysanthemic ester, epiandrosterone you can find the structures of the natural products in Section 4-7.
(a) 3355 cm-1
(b) 1630. 1725. 3030 cm-1
(c) 1730, 3410 cm-1
(d) 1738 cm-1
Q:Identify compounds A, B, and C from the following informationIdentify compounds A, B, and C from the following information and explain the chemistry that is taking place. Reaction of the alcohol shown in the margin with 4-methylbenzenesulfonyl chloride in pyridine produced A (C15H20O3S). Reaction of A with lithium diisopropylamide (I.DA Section 7-8) produces a single product. B (C8H12), which displays m its 1H NMR a two-proton multiplet at about δ = 5.6 ppm. If however, compound A is treated with Nal before the reaction with LDA two products are formed: B and an isomer, C, who’s NMR shows a multiplet at δ = 5.2 ppm that integrates as only one proton.
Q:The citric acid cycle is a series of biological reactionsThe citric acid cycle is a series of biological reactions that plays a central role in cell metabolism. The cycle includes dehydration reactions of both malic and citric acids, yielding fumaric and aconitic acids, respectively (all common names). Both proceed strictly by en/me-catalyzed (/////-elimination mechanisms.
The citric acid cycle is a series of biological reactions

(a) In dehydration only the hydrogen identified by an asterisk is removed, together with the OH group on the carbon below. Write the structures for fumaric and aconitic acids as they are formed in these reactions. Make sure that the stereochemistry of each product is clearly indicated,
(b) Specify the stereochemistry of each of these products, using either cis-trans or E.Z notation, as appropriate,
(c) Isocitric acid (shown in the margin) also is dehydrated by aconi

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