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1 Million+ Step-by-step solutionsmath books Q:How many signals compounds would you expect to see in theHow many signals would you expect to see in the 13C NMR spectrum of each of the following compounds?
(a) Propylbenzene
(d) 1, 2, 4-Trimethylbenzene
(b) Isopropylbenzene
(e) 1, 3, 5-Trimethylbenzene
(c) 1, 2, 3-TrimethylbenzeneQ:Consider carbons x, y, and z in p-methylanisole.Consider carbons x, y, and z in p-methylanisole. One has a chemical shift of δ 20 ppm; another has δ 55 ppm, and the third δ 157 ppm. Match the chemical shifts with the appropriate carbons.Q:To which of the compounds of Problem 13.12To which of the compounds of Problem 13.12 does the 13C NMR spectrum of Figure 13.22 belong?Q:Which one of the following compoundsWhich one of the following compounds is most consistent with the infrared spectrum given in Figure 13.31? Explain your reasoning.Q:Difference in ethylene greater than or less than thatΛmax for the π→π* transition in ethylene is 170 nm. Is the HOMO–LUMO energy difference in ethylene greater than or less than that of cis, trans-1,3-cyclooctadiene?Q:Which one of the C5H8 isomersWhich one of the C5H8 isomers shown has its Λmax at the longest wavelength?Q:Knowing what to look for with respectKnowing what to look for with respect to isotopic clusters can aid in interpreting mass spectra. How many peaks would you expect to see for the molecular ion in each of the following compounds? At what m/z values would these peaks appear? (Disregard the small peaks due to 13C and 2H.)
(a) p-Dichlorobenzene
(c) p-Dibromobenzene
(b) o-Dichlorobenzene
(d) p-BromochlorobenzeneQ:The base peak appears at m/z 105 for oneThe base peak appears at m/z 105 for one of the following compounds and at m/z 119 for the other two. Match the compounds with the appropriate m/z values for their base peaks.Q:How many rings are present in eachHow many rings are present in each of the following compounds? Each consumes 2 moles of hydrogen on catalytic hydrogenation.
(a) C10H18
(d) C8H8O
(b) C8H8
(e) C8H10O2
(c) C8H8CI2
(f) C8H9ClOQ:Each of the following compounds is characterizedEach of the following compounds is characterized by a 1H NMR spectrum that consists of only a single peak having the chemical shift indicated. Identify each compound.
(a) C8H18; δ 0.9 ppm
(f) C2H3Cl3; δ 2.7 ppm
(b) C5H10; δ 1.5 ppm
(g) C5H8Cl4; δ 3.7 ppm
(c) C8H8; δ 5.8 ppm
(h) C12H18; δ 2.2 ppm
(d) C4H9Br; δ 1.8 ppm
(i) C3H6Br2; δ 2.6 ppm
(e) C2H4Cl2; δ 3.7 ppmQ:Each of the following compounds is characterized by a 1HEach of the following compounds is characterized by a 1H NMR spectrum that consists of two peaks, both singlets, having the chemical shifts indicated. Identify each compound.
(a) C6H8; δ 2.7 ppm (4H) and 5.6 ppm (4H)
(b) C5H11Br; δ 1.1 ppm (9H) and 3.3 ppm (2H)
(c) C6H12O; δ 1.1 ppm (9H) and 2.1 ppm (3H)
(d) C6H10O2; δ 2.2 ppm (6H) and 2.7 ppm (4H)Q:Deduce the structure of eachDeduce the structure of each of the following compounds on the basis of their 1H NMR spectra and molecular formulas:
(a) C8H10; δ 1.2 ppm (triplet, 3H)
δ 2.6 ppm (quartet, 2H)
δ 7.1 ppm (broad singlet, 5H)
(b) C10H14;
δ 1.3 ppm (singlet, 9H)
δ 7.0 to 7.5 ppm (multiplet, 5H)
(c) C6H14;
δ 0.8 ppm (doublet, 12H)
(f) C4H6Cl2; 2.2 ppm
(singlet, 3H)
δ 1.4 ppm (heptet, 2H)
δ 4.1 ppm (doublet,
2H)
(d) C6H12;
δ 0.9 ppm (triplet, 3H)
δ 5.7 ppm (triplet,
1H)
δ 1.6 ppm (singlet, 3H)
(g) C3H7ClO; δ 2.0 ppm
(pentet, 2H) δ 1.7 ppm (singlet, 3H)
δ 2.8 ppm (singlet,
1H) δ 2.0 ppm (pentet, 2H)
δ 3.7 ppm (triplet, 2H)
δ 5.1 ppm (triplet, 1H)
δ 3.8 ppm (triplet,
2H)
(e) C4H6Cl4;
δ 3.9 ppm (doublet, 4H)
(h) C14H14; δ 2.9 ppm
(singlet, 4H)
δ 4.6 ppm (triplet, 2H)
δ 7.1 ppm (broad
singlet, 10H)Q:From among the isomeric compoundsFrom among the isomeric compounds of molecular formula C4H9Cl, choose the one having a 1H NMR spectrum that
(a) Contains only a single peak
(b) Has several peaks including a doublet at δ 3.4 ppm
(c) Has several peaks including a triplet at δ 3.5 ppm
(d) Has several peaks including two distinct three-proton signals, one of them a triplet at δ 1.0 ppm and the other a doublet at δ 1.5 ppmQ:Identify the C3H5Br isomersIdentify the C3H5Br isomers on the basis of the following information:
(a) Isomer A has the 1H NMR spectrum shown in Figure 13.40.Q:Identify each of the C4H10O isomersIdentify each of the C4H10O isomers on the basis of their 13C NMR spectra:
(a) δ 18.9 ppm
(CH3) (two carbons)
(c) δ 31.2 ppm (CH3)
(three carbons)
δ 30.8 ppm (CH) (one carbon)
δ 68.9 ppm (C) (one carbon)

δ 69.4 ppm (CH2) (one carbon)
(b) δ 10.0 ppm (CH3)
δ 22.7 ppm (CH3)
δ 32.0 ppm (CH2)
δ 69.2 ppm (CH)Q:Identify the C6H14 isomers on the basisIdentify the C6H14 isomers on the basis of their 13C NMR spectra:
(a) δ 19.1 ppm (CH3)
(d) δ 8.5 ppm (CH3)
δ 33.9 ppm (CH)
δ 28.7 ppm (CH3)
(b) δ 13.7 ppm (CH3)
δ 30.2 ppm (C)
δ 22.8 ppm (CH2)
δ 36.5 ppm (CH2)
δ 31.9 ppm (CH2)
(e) δ 14.0 ppm (CH3)
(c) δ 11.1 ppm (CH3)
δ 20.5 ppm (CH2)
δ 18.4 ppm (CH3)
δ 22.4 ppm (CH3)
δ 29.1 ppm (CH2)
δ 27.6 ppm (CH)
δ 36.4 ppm (CH)
δ 41.6 ppm (CH2)Q:A compound (C4H6) has two signalsA compound (C4H6) has two signals of approximately equal intensity in its 13C NMR spectrum; one is a CH2 carbon at δ 30.2 ppm, the other a CH at δ 136 ppm. Identify the compound.Q:A compound (C3H7ClO2) exhibited three peaksA compound (C3H7ClO2) exhibited three peaks in its 13C NMR spectrum at δ 46.8 (CH2), 63.5 (CH2), and 72.0 ppm (CH). Excluding compounds that have Cl and OH on the same carbon, which are unstable, what is the most reasonable structure for this compound?Q:From among the compounds chlorobenzene,From among the compounds chlorobenzene, o-dichlorobenzene, and p-dichlorobenzene, choose the one that
(a) Gives the simplest 1H NMR spectrum
(b) Gives the simplest 13C NMR spectrum
(c) Has three peaks in its 13C NMR spectrum
(d) Has four peaks in its 13C NMR spectrumQ:Compounds A and B are isomers of molecularCompounds A and B are isomers of molecular formula C10H14. Identify each one on the basis of the 13C NMR spectra presented in Figure 13.41.Q:A compound (C8H10O) has the infraredA compound (C8H10O) has the infrared and 1H NMR spectra presented in Figure 13.42. What is its structure?Q:Deduce the structure of a compound havingDeduce the structure of a compound having the mass spectrum and 1H NMR spectrum presented in Figure 13.43.Q:Figure 13.44 presents several typesFigure 13.44 presents several types of spectroscopic data (IR, 1H NMR, 13C NMR, and mass spectra) for a particular compound. What is it?Q:[18]-Annulene exhibits a 1H NMR spectrum that is unusual[18]-Annulene exhibits a 1H NMR spectrum that is unusual in that in addition to a peak at δ 8.8 ppm, it contains a second peak having a chemical shift δ of – 1.9 ppm. A negative value for the chemical shift δ indicates that the protons are more shielded than those of tetramethylsilane. This peak is 1.9 ppm upfield from the TMS peak. The high-field peak has half the area of the lowfield peak. Suggest an explanation for these observations.

[18]-Annulene exhibits a 1H NMR spectrum that is unusualQ:19F is the only isotope of fluorine that occurs19F is the only isotope of fluorine that occurs naturally, and it has a nuclear spin of + ½
(a) Into how many peaks will the proton signal in the 1H NMR spectrum of methyl fluoride be split?
(b) Into how many peaks will the fluorine signal in the 19F NMR spectrum of methyl fluoride be split?
(c) The chemical shift of the protons in methyl fluoride is 4.3 ppm. Given that the geminal 1H─19F coupling constant is 45 Hz, specify the values at which peaks are observed in the proton spectrum of this compound at 200 MHz.
Q:31P is the only phosphorus isotope present31P is the only phosphorus isotope present at natural abundance and has a nuclear spin of
+- ½. The 1H NMR spectrum of trimethyl phosphite, (CH3O) 3P, exhibits a doublet for the ethyl protons with a splitting of 12 Hz.
(a) Into how many peaks is the 31P signal split?
(b) What is the difference in chemical shift (in hertz) between the lowest and highest field peaks of the 31P multiplet?Q:We noted in section 13.13 that an NMRWe noted in section 13.13 that an NMR spectrum is an average spectrum of the conformations populated by a molecule. From the following data, estimate the percentages of axial and equatorial bromine present in bromocyclohexane.Q:Infrared spectroscopy is an inherently “fasterInfrared spectroscopy is an inherently “faster” method than NMR, and an IR spectrum is a superposition of the spectra of the various conformations, rather than an average of them. When 1, 2-dichloroethane is cooled below its freezing point, the crystalline material gives an IR spectrum consistent with a single species that has a center of symmetry. At room temperature, the IR spectrum of liquid 1, 2-dichloroethane retains the peaks present in the solid, but includes new peaks as well. Explain these observations.Q:Microwave spectroscopy is used to probeMicrowave spectroscopy is used to probe transitions between rotational energy levels in molecules.
(a) A typical wavelength for microwaves is 10-2 m, compared with 10-5 m for infrared radiation. Is the energy separation between rotational energy levels in a molecule greater or less than the separation between vibrational energy levels?
(b) Microwave ovens cook food by heating the water in the food. Absorption of microwave radiation by the water excites it to a higher rotational energy state, and it gives off this excess energy as heat when it relaxes to its ground state. Why are vibrational and electronic energy states not involved in this process?Q:The peak in the UV-VIS spectrum of acetoneThe peak in the UV-VIS spectrum of acetone [(CH3)2C═O] corresponding to the n → π* transition appears at 279 nm when hexane is the solvent, but shifts to 262 nm in water. Which is more polar, the ground electronic state or the excited state?Q:A particular vibration will give an absorptionA particular vibration will give an absorption peak in the infrared spectrum only if the dipole moment of the molecule changes during the vibration. Which vibration of carbon dioxide, the symmetrical stretch or the antisymmetrical stretch, is “infrared-active”?Q:Both of the following organometallicBoth of the following organometallic reagents will be encountered later in this chapter. Suggest a suitable name for each.Q:Write an equation showing the formationWrite an equation showing the formation of each of the following from the appropriate bromide:
(a) Isopropenyllithium
(b) sec-ButyllithiumQ:Write the structure of the GrignardWrite the structure of the Grignard reagent formed from each of the following compounds on reaction with magnesium in diethyl ether:
(a) p-Bromofluorobenzene
(c) Iodocyclobutane
(b) Allyl chloride
(d) 1-BromocyclohexeneQ:Butyllithium is commercially availableButyllithium is commercially available and is frequently used by organic chemists as a strong base. Show how you could use butyllithium to prepare solutions containing
(a) Lithium diethylamide, (CH3CH2)2NLi
(b) Lithium 1-hexanolate, CH3 (CH2)4CH2OLi
(c) Lithium benzenethiolate, C6H5SLiQ:Write the structure of the product of the reaction ofWrite the structure of the product of the reaction of propylmagnesium bromide with each of the following. Assume that the reactions are worked up by the addition of dilute aqueous acid.Q:Write the equation for the reaction of 1-hexyneWrite the equation for the reaction of 1-hexyne with ethylmagnesium bromide as if it involved ethyl anion (CH3CH2) instead of CH3CH2MgBr and use curved arrows to represent the flow of electrons.Q:Suggest two ways in which eachSuggest two ways in which each of the following alcohols might be prepared by using a Grignard reagent:Q:What combination of ester and Grignard reagentWhat combination of ester and Grignard reagent could you use to prepare each of the following tertiary alcohols?Q:Suggest a combination of organic halideSuggest a combination of organic halide and cuprate reagent appropriate for the preparation of each of the following compounds:
(a) 2-Methylbutane
(b) 1, 3, 3-TrimethylcyclopenteneQ:What alkenes would you choose as startingWhat alkenes would you choose as starting materials in order to prepare each of the following cyclopropane derivatives by reaction with iodomethylzinc iodide?Q:The syn stereochemistry of dibromocarbeneThe syn stereochemistry of dibromocarbene cycloaddition was demonstrated in experiments using cis- and trans-2-butene. Give the structure of the product obtained from addition of dibromocarbene to each alkene.Q:Like nickel, iron reacts with carbon monoxideLike nickel, iron reacts with carbon monoxide to form a compound having the formula M (CO)n that obeys the 18-electron rule. What is the value of n in the formula Fe (CO)n?Q:Write structural formulas for eachWrite structural formulas for each of the following compounds. Specify which compounds qualify as organometallic compounds.
(a) Cyclopentyllithium
(d) Lithium divinylcuprate
(b) Ethoxymagnesium chloride
(e) Sodium carbonate
(c) 2-Phenylethylmagnesium iodide
(f) BenzylpotassiumQ:Dibal is an informal name given to the organometallicDibal is an informal name given to the organometallic compound [(CH3)2CHCH2]2AlH, used as a reducing agent in certain reactions. Can you figure out the systematic name from which “dibal” is derived?Q:Suggest appropriate methodsSuggest appropriate methods for preparing each of the following compounds from the starting material of your choice.
(a) CH3CH2CH2CH2CH2MgI
(c) CH3CH2CH2CH2CH2Li
(b) CH3CH2C≡CMgI
(d) (CH3CH2CH2CH2CH2)2CuLiQ:Which compound in each of the following pairs would you expectWhich compound in each of the following pairs would you expect to have the more polar carbon–metal bond? Compare the models on Learning By Modeling with respect to the charge on the carbon bonded to the metal.
(a) CH3CH2Li or (CH3CH2)3Al
(c) CH3CH2MgBr or HC≡CMgBr
(b) (CH3)2Zn or (CH3)2MgQ:Write the structure of the principal organic product of each ofWrite the structure of the principal organic product of each of the following reactions:
(a) 1-Bromopropane with lithium in diethyl ether
(b) 1-Bromopropane with magnesium in diethyl ether
(c) 2-Iodopropane with lithium in diethyl ether
(d) 2-Iodopropane with magnesium in diethyl ether
(e) Product of part (a) with copper (I) iodide
(f) Product of part (e) with 1-bromobutane
(g) Product of part (e) with iodobenzene
(h) Product of part (b) with D2O and DCl
(i) Product of part (c) with D2O and DCl
(j) Product of part (a) with formaldehyde in ether, followed by dilute acid
(k) Product of part (b) with benzaldehyde in ether, followed by dilute acid
(l) Product of part (c) with cycloheptanone in ether, followed by dilute acidQ:Using 1-bromobutane and any necessaryUsing 1-bromobutane and any necessary organic or inorganic reagents, suggest efficient syntheses of each of the following alcohols:
(a) 1-Pentanol
(d) 3-Methyl-3-heptanol
(b) 2-Hexanol
(e) 1-Butylcyclobutanol
(c) 1-Phenyl-1-pentanolQ:Using bromobenzene and any necessary organicUsing bromobenzene and any necessary organic or inorganic reagents, suggest efficient syntheses of each of the following:
(a) Benzyl alcohol
(b) 1-Phenyl-1-hexanol
(c) Bromodiphenylmethane
(e) 1-Phenylcyclooctanol
(d) 4-Phenyl-4-heptano
(f) trans-2-PhenylcyclooctanolQ:Analyze the following structuresAnalyze the following structures so as to determine all the practical combinations of Grignard reagent and carbonyl compound that will give rise to each:Q:A number of drugs are prepared by reactionsA number of drugs are prepared by reactions of the type described in this chapter. Indicate what you believe would be a reasonable last step in the synthesis of each of the following:Q:Predict the principal organic product of each of the following 5838Predict the principal organic product of each of the following reactions:Q:Addition of phenylmagnesium bromide to 4-tertAddition of phenylmagnesium bromide to 4-tert-butylcyclohexanone gives two isomeric tertiary alcohols as products. Both alcohols yield the same alkene when subjected to acid-catalyzed dehydration. Suggest reasonable structures for these two alcohols.Q:(a) Unlike other esters, which react(a) Unlike other esters, which react with Grignard reagents to give tertiary alcohols, ethyl formate (HCOCH2CH3) yields a different class of alcohols on treatment with Grignard reagents. What kind of alcohol is formed in this case and why?
(b) Diethyl carbonate (CH3CH2OCOCH2CH3) reacts with excess Grignard reagent to yield alcohols of a particular type. What is the structural feature that characterizes alcohols prepared in this way?Q:Reaction of lithium diphenylcuprateReaction of lithium diphenylcuprate with optically active 2-bromobutane yields 2-phenylbutane, with high net inversion of configuration, When the 2-bromobutane used has the stereostructure shown, will the 2-phenylbutane formed have the R or the S configuration?Q:Suggest reasonable structures for compoundsSuggest reasonable structures for compounds A, B, and C in the following reactions:Q:The following conversion has been reportedThe following conversion has been reported in the chemical literature. It was carried out in two steps, the first of which involved formation of a p-toluenesulfonate ester. Indicate the reagents for this step, and show how you could convert the p-toluenesulfonate to the desired product.Q:Sometimes the strongly basic properties of GrignardSometimes the strongly basic properties of Grignard reagents can be turned to synthetic advantage. A chemist needed samples of butane specifically labeled with deuterium, the mass 2 isotope of hydrogen, as shown:
(a) CH3CH2CH2CH2D
(b) CH3CHDCH2CH3
Suggest methods for the preparation of each of this using heavy water (D2O) as the source of deuterium, butanols of your choice, and any necessary organic or inorganic reagents.Q:Diphenylmethane is significantly more acidicDiphenylmethane is significantly more acidic than benzene, and triphenylmethane is more acidic than either. Identify the most acidic proton in each compound, and suggest a reason for the trend in acidity.Q:The 18-electron rule is a generalThe 18-electron rule is a general, but not universal, guide for assessing whether a certain transition-metal complex is stable or not. Both of the following are stable compounds, but only one obeys the 18-electron rule. Which one?Q:One of the main uses of the “linear σ-olefins”One of the main uses of the “linear σ-olefins” prepared by oligomerization of ethylene is in the preparation of linear low-density polyethylene. Linear low-density polyethylene is a copolymer produced when ethylene is polymerized in the presence of a “linear σ-olefin” such as 1-decene [CH2 ≡ CH (CH2)7CH3]. 1-Decene replaces ethylene at random points in the growing polymer chain. Can you deduce how the structure of linear low-density polyethylene differs from a linear chain of CH2 units?Q:Each of the following ethers has been shownEach of the following ethers has been shown to be or is suspected to be a mutagen, which means it can induce mutations in test cells. Write the structure of each of these ethers.
(a) Chloromethyl methyl ether
(b) 2-(Chloromethyl)oxirane (also known as epichlorohydrin)
(c) 3, 4-Epoxy-1-butene (2-vinyloxirane)Q:The heats of combustion of 1, 2-epoxybutaneThe heats of combustion of 1, 2-epoxybutane (2-ethyloxirane) and tetrahydrofuran have been measured: one is 2499 kJ/mol (597.8 kcal/mol) the other is 2546 kJ/mol (609.1 kcal/mol). Match the heats of combustion with the respective compounds.Q:Ethers tend to dissolve in alcoholsEthers tend to dissolve in alcohols and vice versa. Represent the hydrogen-bonding interaction between an alcohol molecule and an ether molecule.Q:What organic compound mentioned earlierWhat organic compound mentioned earlier in this chapter is a cyclic dimer of ─OCH2CH2─ unitsQ:Outline a reasonable mechanismOutline a reasonable mechanism for the formation of tert-butyl methyl ether according to the preceding equation.Q:Write equations describing two differentWrite equations describing two different ways in which benzyl ethyl ether could be prepared by a Williamson ether synthesis.Q:Only one combination of alkyl halide and alkoxideOnly one combination of alkyl halide and alkoxide is appropriate for the preparation of each of the following ethers by the Williamson ether synthesis. What is the correct combination in each case?Q:Combustion in air is, of courseCombustion in air is, of course, a chemical property of ethers that is shared by many other organic compounds. Write a balanced chemical equation for the complete combustion (in air) of diethyl ether.Q:A series of dialkyl ethers was allowedA series of dialkyl ethers was allowed to react with excess hydrogen bromide, with the following results. Identify the ether in each case.
(a) One ether gave a mixture of bromocyclopentane and 1-bromobutane.
(b) Another ether gave only benzyl bromide.
(c) A third ether gave one mole of 1, 5-dibromopentane per mole of ether.Q:Adapt the mechanism shown in Figure 16.4Adapt the mechanism shown in Figure 16.4 to the reaction:Q:Is either of the epoxides formed in the precedingIs either of the epoxides formed in the preceding reactions chiral? Is either epoxide optically active when prepared from the alkene by this method?Q:What is the principal organic product formedWhat is the principal organic product formed in the reaction of ethylene oxide with each of the following?
(a) Sodium cyanide (NaCN) in aqueous ethanol
(b) Sodium azide (NaN3) in aqueous ethanol
(c) Sodium hydroxide (NaOH) in water
(d) Phenyllithium (C6H5Li) in ether, followed by addition of dilute sulfuric acid
(e) 1-Butynylsodium (CH3CH2CPCNa) in liquid ammoniaQ:Given the starting material 1-methyl-1Given the starting material 1-methyl-1, 2-epoxycyclopentane, of absolute configuration as shown, decide which one of the compounds A through C correctly represents the product of its reaction with sodium methoxide in methanol.Q:Which product, compound A, B, or CWhich product, compound A, B, or C, would you expect to be formed when 1-methyl-1, 2-epoxycyclopentane of the absolute configuration shown is allowed to stand in methanol containing a few drops of sulfuric acid?Q:Which alkene, cis-2-butene or trans-2-buteneWhich alkene, cis-2-butene or trans-2-butene, would you choose in order to prepare meso-2, 3-butanediol by Epoxidation followed by acidcatalyzed hydrolysis? Which alkene would yield meso-2, 3,-butanediol by osmium tetraoxide hydroxylation?Q:The p-toluenesulfonate derived from (R)-2-octanolThe p-toluenesulfonate derived from (R)-2-octanol and ptoluenesulfonyl chloride was allowed to react with sodium benzenethiolate (C6H5SNa). Give the structure, including stereochemistry and the appropriate R or S descriptor, of the product.Q:Verify, by making molecular modelsVerify, by making molecular models, that the bonds to sulfur are arranged in a trigonal pyramidal geometry in sulfoxides and in a tetrahedral geometry in sulfones. Is phenyl vinyl sulfoxide chiral? What about phenyl vinyl sulfone?Q:What other combination of alkyl halideWhat other combination of alkyl halide and sulfide will yield the same sulfonium salt shown in the preceding example? Predict which combination will yield the sulfonium salt at the faster rate.Q:There is another oxygen-stabilized cationThere is another oxygen-stabilized cation of m/z 87 capable of being formed by fragmentation of the molecular ion in the mass spectrum of secbutyl ethyl ether. Suggest a reasonable structure for this ion.Q:Write the structures of all the constitutionallyWrite the structures of all the constitutionally isomeric ethers of molecular formula C5H12O, and give an acceptable name for each.Q:Many ethers, including diethyl etherMany ethers, including diethyl ether, are effective as general anesthetics. Because simple ethers are quite flammable, their place in medical practice has been taken by highly halogenated nonflammable ethers. Two such general anesthetic agents are isoflurane and enflurane. These compounds are isomeric; isoflurane is 1-chloro-2, 2, 2-trifluoroethyl difluoromethyl ether; enflurane is 2-chloro-1, 1, 2-trifluoroethyl difluoromethyl ether. Write the structural formulas of isoflurane and enflurane.Q:Although epoxides are always consideredAlthough epoxides are always considered to have their oxygen atom as part of a threemembered ring, the prefix epoxy in the IUPAC system of nomenclature can be used to denote a cyclic ether of various sizes.Q:The name of the parent six-memberedThe name of the parent six-membered sulfur-containing heterocycle is thiane. It is numbered beginning at sulfur. Multiple incorporation of sulfur in the ring is indicated by the prefixes di-, tri-, and so on.
(a) How many methyl-substituted thianes are there? Which ones are chiral?
(b) Write structural formulas for 1, 4-dithiane and 1, 3, 5-trithiane.
(c) Which dithiane isomer is a disulfide?
(d) Draw the two most stable conformations of the sulfoxide derived from thiane.Q:The most stable conformation of 1, 3-dioxan-5-olThe most stable conformation of 1, 3-dioxan-5-ol is the chair form that has its hydroxyl group in an axial orientation. Suggest a reasonable explanation for this fact. Building a molecular model is helpful.Q:Outline the steps in the preparation of each of theOutline the steps in the preparation of each of the constitutionally isomeric ethers of molecular formula C4H10O, starting with the appropriate alcohols. Use the Williamson ether synthesis as your key reaction.Q:Predict the principal organic product of each of the following 5874Predict the principal organic product of each of the following reactions. Specify stereochemistry where appropriate.Q:Oxidation of 4-tert-butylthiane with sodiumOxidation of 4-tert-butylthiane with sodium metaperiodate gives a mixture of two compounds of molecular formula C9H18OS. Both products give the same sulfone on further oxidation with hydrogen peroxide. What is the relationship between the two compounds?Q:When (R)-(+)-2-phenyl-2-butanol is allowedWhen (R)-(+)-2-phenyl-2-butanol is allowed to stand in methanol containing a few drops of sulfuric acid; racemic 2-methoxy-2-phenylbutane is formed. Suggest a reasonable mechanism for this reaction.Q:Select reaction conditions that would allowSelect reaction conditions that would allow you to carry out each of the following stereospecific transformations:Q:The last step in the synthesis of divinyl etherThe last step in the synthesis of divinyl ether (used as an anesthetic under the name Vinethene) involves heating ClCH2CH2OCH2CH2Cl with potassium hydroxide. Show how you could prepare the necessary starting material ClCH2CH2OCH2CH2Cl from ethylene.Q:Suggest short, efficient reaction sequencesSuggest short, efficient reaction sequences suitable for preparing each of the following compounds from the given starting materials and any necessary organic or inorganic reagents:Q:Among the ways in which 1, 4-dioxaneAmong the ways in which 1, 4-dioxane may be prepared are the methods expressed in the equations shown:Q:Deduce the identity of the missing compoundsDeduce the identity of the missing compounds in the following reaction sequences. Show stereochemistry in parts (b) through (d).Q:Cineole is the chief componentCineole is the chief component of eucalyptus oil; it has the molecular formula C10H18O and contains no double or triple bonds. It reacts with hydrochloric acid to give the dichloride shown:Q:The p-toluenesulfonate shown undergoesThe p-toluenesulfonate shown undergoes an intramolecular Williamson reaction on treatment with base to give spirocyclic ether. Demonstrate your understanding of the terminology used in the preceding sentence by writing the structure, including stereochemistry, of the product.Q:All the following questions pertain to 1H NMRAll the following questions pertain to 1H NMR spectra of isomeric ethers having the molecular formula C5H12O.
(a) Which one has only singlets in its 1H NMR spectrum?
(b) Along with other signals, this ether has a coupled doublet–septet pattern. None of the protons responsible for this pattern are coupled to protons anywhere else in the molecule.
Identify this ether.
(c) In addition to other signals in its 1H NMR spectrum, this ether exhibits two signals at relatively low field. One is a singlet; the other is a doublet. What is the structure of this ether?
(d) In addition to other signals in its 1H NMR spectrum, this ether exhibits two signals at relatively low field. One is a triplet; the other is a quartet. Which ether is this?Q:The 1H NMR spectrum of compound A (C8H8O)The 1H NMR spectrum of compound A (C8H8O) consists of two singlets of equal area at δ 5.1 (sharp) and 7.2 ppm (broad). On treatment with excess hydrogen bromide, compound A is converted to a single dibromide (C8H8Br2). The 1H NMR spectrum of the dibromide is similar to that of A in that it exhibits two singlets of equal area at δ 4.7 (sharp) and 7.3 ppm (broad). Suggest reasonable structures for compound A and the dibromide derived from it.Q:The 1H NMR spectrum of a compound (C10H13BrO)The 1H NMR spectrum of a compound (C10H13BrO) is shown in Figure 16.10. The compound gives benzyl bromide, along with a second compound C3H6Br2, when heated with HBr. What is the first compound? Showing 500 – 600 of 15569 45678 > >> Join SolutionInn Study Help for 1 Million+ Textbook Solutions Learn the step-by-step answers to your textbook problems, just enter our Solution Library containing more than 1 Million+ textbooks solutions and help guides from over 1300 courses. 24/7 Online Tutors Tune up your concepts by asking our tutors any time around the clock and get prompt responses. Start Membership ×NO, THANKSTRY NOW

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