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1 Million+ Step-by-step solutionsmath books Q:A subrule of the Cahn–Ingold–Prelog systemA subrule of the Cahn–Ingold–Prelog system specifies that higher mass number takes precedence over lower when distinguishing between isotopes. (a) Determine the absolute configurations of the reactant and product in the biological oxidation of isotopically labeled ethane described in Section 7.2.Q:Identify the relationship in each of the following pairs.Identify the relationship in each of the following pairs. Do the drawings represent constitutional isomers or stereoisomers, or are they just different ways of drawing the same compound? If they are stereoisomers, are they enantiomers or diastereomers? (Molecular models may prove useful in this problem.)Q:Chemical degradation of chlorophyll gives a numberChemical degradation of chlorophyll gives a number of substances including phytol. The constitution of phytol is given by the name 3, 7, 11, 15-tetramethyl-2-hexadecen-1-ol. How many stereoisomers have this constitution?Q:Muscarine is a poisonous substance presentMuscarine is a poisonous substance present in the mushroom Amanita muscaria. Its structure is represented by the constitution shown.Q:Ectocarpene is a volatile, sperm cell-attractingEctocarpene is a volatile, sperm cell-attracting material released by the eggs of the seaweed Ectocarpus siliculosus. Its constitution isQ:Multifidene is a sperm cell-attracting substanceMultifidene is a sperm cell-attracting substance released by the female of a species of brown algae (Cutleria multifida). The constitution of multifidene isQ:Streptimidone is an antibiotic and has the structureStreptimidone is an antibiotic and has the structure shown. How many diastereomers of Streptimidone are possible? How many enantiomers? Using the E, Z and R, S descriptors, specify all essential elements of stereochemistry of Streptimidone.Q:In Problem 4.26 you were asked to draw the preferredIn Problem 4.26 you were asked to draw the preferred conformation of menthol on the basis of the information that menthol is the most stable stereoisomer of 2-isopropyl-5-methylcyclohexanol. We can now completely describe (+)-menthol structurally by noting that it has the R configuration at the hydroxyl-substituted carbon.
(a) Draw or construct a molecular model of the preferred conformation of (+)-menthol.
(b) (+)-Isomenthol has the same constitution as (+)-menthol. The configurations at C-1 and C-2 of (+)-isomenthol are the opposite of the corresponding stereogenic centers of (+)-menthol. Write the preferred conformation of (+)-isomenthol.Q:A certain natural product having [a] D+ 40.3°A certain natural product having [a] D+ 40.3° was isolated. Two structures have been independently proposed for this compound. Which one do you think is more likely to be correct? Why?Q:One of the principal substances obtainedOne of the principal substances obtained from archaea (one of the oldest forms of life on earth) is derived from a 40-carbon diol. Given the fact that this diol is optically active, is it compound A or is it compound B?Q:(a) An aqueous solution containing 10 g of optically(a) An aqueous solution containing 10 g of optically pure fructose was diluted to 500 mL with water and placed in a polarimeter tube 20 cm long. The measured rotation was _5.20°. Calculate the specific rotation of fructose.
(b) If this solution were mixed with 500 mL of a solution containing 5 g of racemic fructose, what would be the specific rotation of the resulting fructose mixture? What would be its optical purity?Q:Write the organic products of eachWrite the organic products of each of the following reactions. If two stereoisomers are formed, show both. Label all stereogenic centers R or S as appropriate.
(a) 1-Butene and hydrogen iodide
(b) (E)-2-Pentene and bromine in carbon tetrachloride
(c) (Z)-2-Pentene and bromine in carbon tetrachloride
(d) 1-Butene and peroxyacetic acid in dichloromethane
(e) (Z)-2-Pentene and peroxyacetic acid in dichloromethane
(f) 1, 5, 5-Trimethylcyclopentene and hydrogen in the presence of platinum
(g) 1, 5, 5-Trimethylcyclopentene and diborane in tetrahydrofuran followed by oxidation with hydrogen peroxideQ:The enzyme aconitase catalyzes the hydrationThe enzyme aconitase catalyzes the hydration of aconitic acid to two products: citric acid and isocitric acid. Isocitric acid is optically active; citric acid is not. What are the respective constitutions of citric acid and isocitric acid?Q:Consider the ozonolysis of trans-4, 5Consider the ozonolysis of trans-4, 5-dimethylcyclohexene having the configuration shown.Q:(a) On being heated with potassium ethoxide(a) On being heated with potassium ethoxide in ethanol (70°C), the deuterium-labeled alkyl bromide shown gave a mixture of 1-butene, cis-2-butene, and trans-2-butene. On the basis of your knowledge of the E2 mechanism, predict which alkene(s), if any, contained deuterium.Q:A compound (C6H10) contains a five-memberedA compound (C6H10) contains a five-membered ring. When Br2 adds to it, two diastereomeric dibromides are formed. Suggest reasonable structures for the compound and the two dibromides.Q:When optically pure 2, 3-dimethyl-2-pentanolWhen optically pure 2, 3-dimethyl-2-pentanol was subjected to dehydration, a mixture of two alkenes was obtained. Hydrogenation of this alkene mixture gave 2, 3-dimethylpentane, which was 50% optically pure. What were the two alkenes formed in the elimination reaction, and what were the relative amounts of each?Q:When (R)-3-buten-2-ol is treatedWhen (R)-3-buten-2-ol is treated with a peroxy acid, two stereoisomeric epoxides are formed in a 60:40 ratio. The minor stereoisomer has the structure shown.Q:Use curved arrows to show how calcium carbideUse curved arrows to show how calcium carbide reacts with water to give acetylene.Q:Write structural formulas and give the IUPAC names for allWrite structural formulas and give the IUPAC names for all the alkynes of molecular formula C5H8.Q:How do bond distances and bond strengths changeHow do bond distances and bond strengths change with electronegativity in the series NH3, H2O, and HF?Q:Complete each of the following equationsComplete each of the following equations to show the conjugate acid and the conjugate base formed by proton transfer between the indicated species. Use curved arrows to show the flow of electrons, and specify whether the position of equilibrium lies to the side of reactants or products.Q:Outline efficient synthesesOutline efficient syntheses of each of the following alkynes from acetylene and any necessary organic or inorganic reagents:
(a) 1-Heptyne
(b) 2-Heptyne
(c) 3-HeptyneQ:Which of the alkynes of molecular formula C5H8Which of the alkynes of molecular formula C5H8 can be prepared in good yield by alkylation or, dialkylation of acetylene? Explain why the preparation of the other C5H8 isomers would not be practical.Q:Give the structures of three isomeric dibromidesGive the structures of three isomeric dibromides that could be used as starting materials for the preparation of 3,3-dimethyl-1-butyne.Q:Show, by writing an appropriate seriesShow, by writing an appropriate series of equations, how you could prepare propyne from each of the following compounds as starting materials, You may use any necessary organic or inorganic reagents.
(a) 2-Propanol
(d) 1, 1-Dichloroethane
(b) 1-Propanol
(e) Ethyl alcohol
(c) Isopropyl bromideQ:Write a series of equations showing how you could prepareWrite a series of equations showing how you could prepare octane from acetylene and any necessary organic and inorganic reagents.Q:Oleic acid and stearic acid are naturally occurringOleic acid and stearic acid are naturally occurring compounds, which can be isolated from various fats and oils. In the laboratory, each can be prepared by hydrogenation of a compound known as stearolic acid, which has the formula CH3 (CH2)7CPC (CH2)7CO2H. Oleic acid is obtained by hydrogenation of tearolic acid over Lindlar palladium; stearic acid is obtained by hydrogenation over platinum. What are the structures of oleic acid and stearic acid?Q:Sodium–ammonia reduction of stearolic acidSodium–ammonia reduction of stearolic acid (see Problem 9.10) yields a compound known as elaidic acid. What is the structure of elaidic acid?Q:Suggest efficient syntheses of (E) – and (Z)-2-hepteneSuggest efficient syntheses of (E) – and (Z)-2-heptene from propyne and any necessary organic or inorganic reagents.Q:Write a series of equations showing how you could prepare 1,Write a series of equations showing how you could prepare 1, 1-dichloroethane from
(a) Ethylene
(b) Vinyl chloride (CH2 = CHCl)
(c) 1, 1-DibromoethanQ:Give the structure of the enol formed by hydrationGive the structure of the enol formed by hydration of 2-butyne, and write a series of equations showing its conversion to its corresponding ketone isomer.Q:Show by a series of equations how you could prepareShow by a series of equations how you could prepare 2-octanone from acetylene and any necessary organic or inorganic reagents. How could you prepare 4-octanone?Q:A certain hydrocarbon had the molecular formulaA certain hydrocarbon had the molecular formula C16H26 and contained two triple bonds. Ozonolysis gave CH3 (CH2)4CO2H and HO2CCH2CH2CO2H as the only products. Suggest a reasonable structure for this hydrocarbon.Q:Write structural formulas and give the IUPAC namesWrite structural formulas and give the IUPAC names for all the alkynes of molecular formula C6H10.Q:Provide the IUPAC name for each of the followingProvide the IUPAC name for each of the following alkynes:
(a) CH3CH2CH2CP ≡ CH
(b) CH3CH2CP ≡ CCH3
(c) CH3C ≡ CHCH (CH3)2
CH3Q:Write a structural formula or build a molecularWrite a structural formula or build a molecular model of each of the following:
(a) 1-Octyne
(b) 2-Octyne
(c) 3-Octyne
(d) 4-Octyne
(e) 2, 5-Dimethyl-3-hexyne
(f) 4-Ethyl-1-hexyne
(g) Ethynylcyclohexane
(h) 3-Ethyl-3-methyl-1-pentyneQ:All the compounds in Problem 9.19 are isomers exceptAll the compounds in Problem 9.19 are isomers except one. Which one?Q:Write structural formulas for all the alkynesWrite structural formulas for all the alkynes of molecular formula C8H14 that yield 3-ethylhexane on catalytic hydrogenation.Q:An unknown acetylenic amino acid obtainedAn unknown acetylenic amino acid obtained from the seed of a tropical fruit has the molecular formula C7H11NO2- On catalytic hydrogenation over platinum this amino acid yielded homoleucine (an amino acid of known structure shown here) as the only product. What is the structure of the unknown amino acid?
Homoleucine
CH3CH2CHCH2CHCO─
CH3
+NH3Q:Show by writing appropriate chemical equations how each of theShow by writing appropriate chemical equations how each of the following compounds could be converted to 1-hexyne:
(a) 1, 1-Dichlorohexane (c) Acetylene
(b) 1-Hexene (d) 1-IodohexaneQ:Show by writing appropriate chemical equations how each of the followingShow by writing appropriate chemical equations how each of the following compounds could be converted to 3-hexyne:
(a) 1-Butene
(b) 1, 1-Dichlorobutane
(c) AcetyleneQ:When 1, 2-dibromodecane was treated with potassiumWhen 1, 2-dibromodecane was treated with potassium hydroxide in aqueous ethanol, it yielded a mixture of three isomeric compounds of molecular formula C10H19Br. Each of these compounds was converted to 1-decyne on reaction with sodium amide in dimethyl sulfoxide. Identify these three compounds.Q:Write the structure of the major organic product isolated fromWrite the structure of the major organic product isolated from the reaction of 1-hexyne with
(a) Hydrogen (2 mol), platinum
(b) Hydrogen (1 mol), Lindlar palladium
(c) Lithium in liquid ammonia
(d) Sodium amide in liquid ammonia
(e) Product in part (d) treated with 1-bromobutane
(f ) Product in part (d) treated with tert-butyl bromide
(g) Hydrogen chloride (1 mol)
(h) Hydrogen chloride (2 mol)
(i) Chlorine (1 mol)
(j) Chlorine (2 mol)
(k) Aqueous sulfuric acid, mercury (II) sulfate
(l) Ozone followed by hydrolysisQ:Write the structure of the major organic product isolated from theWrite the structure of the major organic product isolated from the reaction of 3-hexyne with
(a) Hydrogen (2 mol), platinum
(b) Hydrogen (1 mol), Lindlar palladium
(c) Lithium in liquid ammonia
(d) Hydrogen chloride (1 mol)
(e) Hydrogen chloride (2 mol)
(f) Chlorine (1 mol)
(g) Chlorine (2 mol)
(h) Aqueous sulfuric acid, mercury (II) sulfate
(i) Ozone followed by hydrolysisQ:When 2-heptyne was treated with aqueous sulfuricWhen 2-heptyne was treated with aqueous sulfuric acid containing mercury (II) sulfate, two products, each having the molecular formula C7H14O, were obtained in approximately equal amounts. What are these two compounds?Q:The alkane formed by hydrogenation of (S)-4-methyl-1The alkane formed by hydrogenation of (S)-4-methyl-1-hexyne is optically active, but the one formed by hydrogenation of (S)-3-methyl-1-pentyne is not. Explain. Would you expect the products of hydrogenation of these two compounds in the presence of Lindlar palladium to be optically active?Q:All the following reactions have been describedAll the following reactions have been described in the chemical literature and proceed in good yield. In some cases the reactants are more complicated than those we have so far encountered. Nevertheless, on the basis of what you have already learned, you should be able to predict the principal product in each case.

All the following reactions have been describedQ:The ketone 2-heptanone has been identifiedThe ketone 2-heptanone has been identified as contributing to the odor of a number of dairy products, including condensed milk and cheddar cheese. Describe a synthesis of 2-heptanone from acetylene and any necessary organic or inorganic reagents.Q:(Z)-9-Tricosene [(Z)-CH3 (CH2)7CH=CH (CH2)12CH3](Z)-9-Tricosene [(Z)-CH3 (CH2)7CH=CH (CH2)12CH3] is the sex pheromone of the female housefly. Synthetic (Z)-9-tricosene is used as bait to lure male flies to traps that contain insecticide. Using acetylene and alcohols of your choice as starting materials, along with any necessary inorganic reagents, show how you could prepare (Z)-9-tricosene.Q:Show by writing a suitable series of equationsShow by writing a suitable series of equations how you could prepare each of the following compounds from the designated starting materials and any necessary organic or inorganic reagents:
(a) 2, 2-Dibromopropane from 1, 1-dibromopropane
(b) 2, 2-Dibromopropane from 1, 2-dibromopropane
(c) 1, 1, 2, 2-Tetrachloropropane from 1, 2-dichloropropane
(d) 2, 2-Diiodobutane from acetylene and ethyl bromide
(e) 1-Hexene from 1-butene and acetylene
(f ) Decane from 1-butene and acetylene
(g) Cyclopentadecyne from cyclopentadeceneQ:Assume that you need to prepare 4-methyl-2-pentyneAssume that you need to prepare 4-methyl-2-pentyne and discover that the only alkynes on hand are acetylene and propyne. You also have available methyl iodide, isopropyl bromide, and 1, 1-dichloro-3-methylbutane. Which of these compounds would you choose in order to perform your synthesis, and how would you carry it out?Q:Compound A has the molecular formula C14H25BrCompound A has the molecular formula C14H25Br and was obtained by reaction of sodium acetylide with 1,12-dibromododecane. On treatment of compound A with sodium amide, it was converted to compound B (C14H24). Ozonolysis of compound B gave the diacid HO2C (CH2)12CO2H. Catalytic hydrogenation of compound B over Lindlar palladium gave compound C (C14H26), and hydrogenation over platinum gave compound D (C14H28). Sodium–ammonia reduction of compound B gave compound E (C14H26). Both C and E yielded OoeCH (CH2)12CHoeO on ozonolysis. Assign structures to compounds A through E so as to be consistent with the observed transformations.Q:Write a structural formula for the principal organicWrite a structural formula for the principal organic product formed in the reaction of methyl bromide with each of the following compounds:
(a) NaOH (sodium hydroxide)
(b) KOCH2CH3 (potassium ethoxide)Q:A single organic product was obtained when 1-bromo-3A single organic product was obtained when 1-bromo-3-chloropropane was allowed to react with one molar equivalent of sodium cyanide in aqueous ethanol. What was this product?Q:Is the two-step sequence depicted in the followingIs the two-step sequence depicted in the following equations consistent with the second-order kinetic behavior observed for the hydrolysis of methyl bromide?Q:The Fischer projection formula for (+)-2-bromooctaneThe Fischer projection formula for (+)-2-bromooctane is shown. Write the Fischer projection of the (+)-2-octanol formed from it by nucleophilic substitution with inversion of configuration.Q:Would you expect the 2-octanol formed by SN2Would you expect the 2-octanol formed by SN2 hydrolysis of (+) – 2-bromooctane to be optically active? If so, what will be its absolute configuration and sign of rotation? What about the 2-octanol formed by hydrolysis of racemic 2-bromooctane?Q:Sodium nitrite (NaNO2) reacted with 2-iodooctaneSodium nitrite (NaNO2) reacted with 2-iodooctane to give a mixture of two constitutionally isomeric compounds of molecular formula C8H17NO2 in a combined yield of 88%. Suggest reasonable structures for these two isomers.Q:Suggest a structure for the product of nucleophilicSuggest a structure for the product of nucleophilic substitution obtained on Solvolysis of tert-butyl bromide in methanol, and outline a reasonable mechanism for its formation.Q:Identify the compound in each of the following pairs thatIdentify the compound in each of the following pairs that reacts at the faster rate in an SN1 reaction:
(a) Isopropyl bromide or isobutyl bromide
(b) Cyclopentyl iodide or 1-methylcyclopentyl iodide
(c) Cyclopentyl bromide or 1-bromo-2, 2-dimethylpropane
(d) tert-Butyl chloride or tert-butyl iodideQ:Identify the compound in each of the following pairs that reactsIdentify the compound in each of the following pairs that reacts with sodium iodide in acetone at the faster rate:
(a) 1-Chlorohexane or cyclohexyl chloride
(b) 1-Bromopentane or 3-bromopentane
(c) 2-Chloropentane or 2-fluoropentane
(d) 2-Bromo-2-methylhexane or 2-bromo-5-methylhexane
(e) 2-Bromopropane or 1-bromodecaneQ:What two stereoisomeric substitution products wouldWhat two stereoisomeric substitution products would you expect to isolate from the hydrolysis of cis-1, 4-dimethylcyclohexyl bromide? From hydrolysis of trans-1, 4-dimethylcyclohexyl bromideQ:Why does the carbocation intermediateWhy does the carbocation intermediate in the hydrolysis of 2-bromo-3-methylbutane rearrange by way of a hydride shift rather than a methyl shift?Q:Predict the major organic product of each of the followingPredict the major organic product of each of the following reactions:
(a) Cyclohexyl bromide and potassium ethoxide
(b) Ethyl bromide and potassium cyclohexanolate
(c) sec-Butyl bromide solvolysis in methanol
(d) sec-Butyl bromide solvolysis in methanol containing 2 M sodium methoxideQ:Write a chemical equation showing the preparationWrite a chemical equation showing the preparation of octadecyl p-toluenesulfonate.Q:Write equations showing the reaction of octadecylWrite equations showing the reaction of octadecyl p-toluenesulfonate with each of the following reagents:
(a) Potassium acetate (KOCCH3)
(b) Potassium iodide (KI)
(c) Potassium cyanide (KCN)
(d) Potassium hydrogen sulfide (KSH)
(e) Sodium butanethiolate (NaSCH2CH2CH2CH3)Q:The hydrolysis of sulfonate esters of 2-octanolThe hydrolysis of sulfonate esters of 2-octanol is a stereospecific reaction and proceeds with complete inversion of configuration. Write a structural formula that shows the stereochemistry of the 2-octanol formed by hydrolysis of an optically pure sample of (S)-(+)-1-methylheptyl p-toluenesulfonate, identify the product as R or S, and deduce its specific rotation.Q:Treatment of 3-methyl-2-butanol with hydrogenTreatment of 3-methyl-2-butanol with hydrogen chloride yielded only a trace of 2-chloro-3-methylbutane. An isomeric chloride was isolated in 97% yield. Suggest a reasonable structure for this product.Q:Write the structure of the principal organic productWrite the structure of the principal organic product to be expected from the reaction of
1-bromopropane with each of the following:
(a) Sodium iodide in acetone (CH3CONa)
(b) Sodium acetate in acetic acid
(c) Sodium ethoxide in ethanol
(d) Sodium cyanide in dimethyl sulfoxide
(e) Sodium azide in aqueous ethanol
(f) Sodium hydrogen sulfide in ethanol
(g) Sodium methanethiolate (NaSCH3) in ethanolQ:All the reactions of 1-bromopropane in the precedingAll the reactions of 1-bromopropane in the preceding problem give the product of nucleophilic substitution in high yield. High yields of substitution products are also obtained in all but one of the analogous reactions using 2-bromopropane as the substrate. In one case, however, 2-bromopropane is converted to propane, especially when the reaction is carried out at elevated temperature (about 55°C). Which reactant is most effective in converting 2-bromopropane to propane?Q:Each of the following nucleophilic substitutionEach of the following nucleophilic substitution reactions has been reported in the chemical literature. Many of them involve reactants that are somewhat more complex than those we have dealt with to this point. Nevertheless, you should be able to predict the product by analogy to what you know about nucleophilic substitution in simple systems.Q:Each of the reactions shown involves nucleophilicEach of the reactions shown involves nucleophilic substitution. The product of reaction (a) s an isomer of the product of reaction
(b) What kind of isomer? By what mechanism does nucleophilic substitution occur? Write the structural formula of the product of each reaction.Q:Arrange the isomers of molecular formula C4H9ClArrange the isomers of molecular formula C4H9Cl in order of decreasing rate of reaction with sodium iodide in acetone.Q:There is an overall 29-fold differenceThere is an overall 29-fold difference in reactivity of 1-chlorohexane, 2-chlorohexane, and 3-chlorohexane toward potassium iodide in acetone. (a) Which one is the most reactive? Why?
(b) Two of the isomers differ by only a factor of 2 in reactivity. Which two are these?
Which one is the more reactive? Why?Q:In each of the following indicate which reactionIn each of the following indicate which reaction will occur faster. Explain your reasoning.
(a) CH3CH2CH2CH2Br or CH3CH2CH2CH2I with sodium cyanide in dimethyl sulfoxide
(b) 1-Chloro-2-methylbutane or 1-chloropentane with sodium iodide in acetone
(c) Hexyl chloride or cyclohexyl chloride with sodium azide in aqueous ethanol
(d) Solvolysis of 1-bromo-2,2-dimethylpropane or tert-butyl bromide in ethanol
(e) Solvolysis of isobutyl bromide or sec-butyl bromide in aqueous formic acid
(f) Reaction of 1-chlorobutane with sodium acetate in acetic acid or with sodium methoxide in methanol
(g) Reaction of 1-chlorobutane with sodium azide or sodium p-toluenesulfonate in aqueous ethanolQ:Under conditions of photochemical chlorinationUnder conditions of photochemical chlorination, (CH3)3CCH2C (CH3)3 gave a mixture of two monochlorides in a 4:1 ratio. The structures of these two products were assigned on the basis of their SN1 hydrolysis rates in aqueous ethanol. The major product (compound A) underwent hydrolysis much more slowly than the minor one (compound B). Deduce the structures of compounds A and B.Q:The compound KSCN is a source of thiocyanate ion.The compound KSCN is a source of thiocyanate ion.
(a) Write the two most stable Lewis structures for thiocyanate ion and identify the atom in each that bears a formal charge of _1.
(b) Two constitutionally isomeric products of molecular formula C5H9NS were isolated in a combined yield of 87% in the reaction shown. (DMF stands for N, N-dimethylformamide, a polar aprotic solvent.) Suggest reasonable structures for these two compounds.Q:Reaction of ethyl iodide with triethylamineReaction of ethyl iodide with triethylamine yields a crystalline compound C8H20NI in high yield. This compound is soluble in polar solvents such as water but insoluble in nonpolar ones such as diethyl ether. It does not melt below about 200°C. Suggest a reasonable structure for this product.Q:Write an equation, clearly showing the stereochemistryWrite an equation, clearly showing the stereochemistry of the starting material and the product, for the reaction of (S)-1-bromo-2-methylbutane with sodium iodide in acetone. What is the configuration (R or S) of the product?Q:Identify the product in each of the following reactions:Identify the product in each of the following reactions:Q:Give the mechanistic symbols (SN1, SN2, E1, E2)Give the mechanistic symbols (SN1, SN2, E1, E2) that are most consistent with each of the following statements:
(a) Methyl halides react with sodium ethoxide in ethanol only by this mechanism.
(b) Unhindered primary halides react with sodium ethoxide in ethanol mainly by this mechanism.
(c) When cyclohexyl bromide is treated with sodium ethoxide in ethanol, the major product is formed by this mechanism.
(d) The substitution product obtained by solvolysis of tert-butyl bromide in ethanol arises by this mechanism.
(e) In ethanol that contains sodium ethoxide, tert-butyl bromide reacts mainly by this mechanism.
(f) These reaction mechanisms represent concerted processes.
(g) Reactions proceeding by these mechanisms are stereospecific.
(h) These reaction mechanisms involve carbocation intermediates.
(i) These reaction mechanisms are the ones most likely to have been involved when the products are found to have a different carbon skeleton from the substrate.
(j) Alkyl iodides react faster than alkyl bromides in reactions that proceed by these mechanisms.Q:Outline an efficient synthesis of each of the followingOutline an efficient synthesis of each of the following compounds from the indicated starting material and any necessary organic or inorganic reagents:
(a) Cyclopentyl cyanide from cyclopentane
(b) Cyclopentyl cyanide from cyclopentene
(c) Cyclopentyl cyanide from cyclopentanol
(d) NCCH2CH2CN from ethyl alcohol
(e) Isobutyl iodide from isobutyl chloride
(f) Isobutyl iodide from tert-butyl chloride
(g) Isopropyl azide from isopropyl alcohol
(h) Isopropyl azide from 1-propanol
(i) (S)-sec-Butyl azide from (R)-sec-butyl alcohol
(j) (S)-CH3CH2CHCH3 from (R)-sec-butyl alcoholQ:Select the combination of alkyl bromide and potassiumSelect the combination of alkyl bromide and potassium alkoxide that would be the most effective in the syntheses of the following ethers:Q:Alkynes of the type RCPCH may be preparedAlkynes of the type RCPCH may be prepared by nucleophilic substitution reactions in which one of the starting materials is sodium acetylide
(a) Devise a method for the preparation of CH3CH2C ≡ CH from sodium acetylide and any necessary organic or inorganic reagents.
(b) Given the information that Ka for acetylene (HC ≡ CH) is 10-26 (pKa 26) comment on the scope of this preparative procedure with respect to R in RC ≡ CH. Could you prepare (CH3)2CHC ≡ CH or (CH3)3CC ≡ CH in good yield by this method?Q:Give the structures, including stereochemistry, of compounds A and BGive the structures, including stereochemistry, of compounds A and B in the following sequence of reactions:Q:(a) Suggest a reasonable series of synthetic(a) Suggest a reasonable series of synthetic transformations for converting trans-2-methylcyclopentanol to cis-2-methylcyclopentyl acetate.Q:Optically pure (S)-(+)-2-butanol was convertedOptically pure (S)-(+)-2-butanol was converted to its methanesulfonate ester according to the reaction shown.Q:In a classic experiment, Edward HughesIn a classic experiment, Edward Hughes (a colleague of in gold’s at University College, London) studied the rate of racemization of 2-iodooctane by sodium iodide in acetone and compared it with the rate of incorporation of radioactive iodine into 2-iodooctaneQ:The ratio of elimination to substitution is exactlyThe ratio of elimination to substitution is exactly the same (26% elimination) for 2-bromo-2-methylbutane and 2-iodo-2-methylbutane in 80% ethanol/20% water at 25°C.
(a) By what mechanism does substitution most likely occur in these compounds under these conditions?
(b) By what mechanism does elimination most likely occur in these compounds under these conditions?
(c) Which substrate undergoes substitution faster?
(d) Which substrate undergoes elimination faster?
(e) What two substitution products are formed from each substrate?
(f) What two elimination products are formed from each substrate?
(g) Why do you suppose the ratio of elimination to substitution is the same for the two substrates?Q:The reaction of 2, 2-dimethyl-1-propanol with HBrThe reaction of 2, 2-dimethyl-1-propanol with HBr is very slow and gives 2-bromo-2 methyl propane as the major product.Q:Solvolysis of 2-bromo-2-methylbutane in acetic acidSolvolysis of 2-bromo-2-methylbutane in acetic acid containing potassium acetate gave three products. Identify them.Q:Solvolysis of 1, 2-dimethylpropyl p-toluenesulfonateSolvolysis of 1, 2-dimethylpropyl p-toluenesulfonate in acetic acid (75°C) yields five different products: three are alkenes and two are substitution products. Suggest reasonable structures for these five products.Q:Solution A was prepared by dissolving potassiumSolution A was prepared by dissolving potassium acetate in methanol. Solution B was prepared by adding potassium methoxide to acetic acid. Reaction of methyl iodide either with solution A or with solution B gave the same major product. Why? What was this product?Q:If the temperature is not kept below 25°C duringIf the temperature is not kept below 25°C during the reaction of primary alcohols with ptoluenesulfonyl chloride in pyridine, it is sometimes observed that the isolated product is not the desired alkyl p-toluenesulfonate but is instead the corresponding alkyl chloride. Suggest a mechanistic explanation for this observation.Q:The reaction of cyclopentyl bromide with sodiumThe reaction of cyclopentyl bromide with sodium cyanide to give cyclopentyl cyanideQ:Write structural formulas for toluene (C6H5CH3)Write structural formulas for toluene (C6H5CH3) and for benzoic acid (C6H5CO2H) (a) as resonance hybrids of two Kekule forms and (b) with the Robinson symbol.Q:The heats of hydrogenation of cyclohepteneThe heats of hydrogenation of cycloheptene and 1, 3, 5-cycloheptatriene are 110 kJ/mol (26.3 kcal/mol) and 305 kJ/mol (73.0 kcal/mol), respectively. In both cases cycloheptane is the product. What is the resonance energy of 1, 3, 5-cycloheptatriene? How does it compare with the resonance energy of benzene?Q:Write a structural formula for each of the following compounds: (a) 5684Write a structural formula for each of the following compounds:
(a) o-Ethylanisole (c) p-Nitroaniline
(b) m-ChlorostyreneQ:Chrysene is an aromatic hydrocarbon foundChrysene is an aromatic hydrocarbon found in coal tar. The structure shown is not the most s

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