Questions and Answers of Organic Chemistry 4th

Show the structures of the intermediate hemiacetals and the final acetals that result from the following reactions: (a) (b) + CH3CH₂CCH₂CH3 + OH T CH3CHCH3 H+ catalyst -OH H+ catalyst
Write the products you would obtain from treatment of cyclohexanone with the following:(a) CH3NH2 (b) CH3CH2OH, H(c) NaBH4
Show the products from the reaction of pentan-2-one with the following reagents. (a) NH₂OH (b) 0₂N -NHNH2 NO₂ (c) CH3CH₂OH, H+
How could you make the following alcohols using a Grignard reaction of an aldehyde or ketone? Show all possibilities. (a) CH3 CH3CHCH₂CH₂CH₂OH (b) OH (c) OH CH3CH₂CHCH=CHCH3
Show the structures of the alcohols and aldehydes or ketones you would use to make the following acetals: (a) CH3 OCH3 T CH3CH₂CHCH₂CHOCH3 (b) CH3CH₂O OCH₂CH3 CH3 (c) ∞
When glucose is treated with NaBH4, reaction occurs to yield sorbitol, a commonly used food additive. Show how this reduction occurs.
Draw structures corresponding to the following names:(a) Bromoacetone (b) 3-Methylbutan-2-one(c) 3,5-Dinitrobenzaldehyde (d) 3,5-Dimethylcyclohexanone(e)
How can you explain the observation that the SN2 reaction of (dibromomethyl)benzene with NaOH yields benzaldehyde rather than (dihydroxymethyl)benzene?
Show the products that result from the reaction of phenylmagnesium bromide with the following reagents:(a) CH2O(b) Benzophenone (C6H5COC6H5)(c) Pentan-3-one
Many insecticides function by blocking cellular receptors for the insect molting hormone ecdysone. HO. HO Н CH3 I H H3C CH3 OH Ecdysone Н Н -OH H3C -OH CH3
Give IUPAC names for the following acyl derivatives: (a) (d) CH3 CH3CHCH2CH2CCI ال (g) 0 0=0 H2C = CHCH2CH2CNHCH3 (b) (e) (h) CH₂CNH2 || OCHCH3 CH3 CH3 CH3CH2CHCN (c) (f) CH3CHCOCHCH3 CH3
Ketones react with dimethyl sulfonium methylide to yield epoxides by a mechanism that involves (1) an initial nucleophilic addition followed by (2) an intramolecular SN2 substitution. Show the
Reaction of butan-2-one with HCN yields a cyanohydrin product [R2C(OH)CN] having a new chirality center. Explain why the product is not optically active.
Identify the reagents a through d in the following scheme: H OH the ro CH30 0CH3 ство прода Br Br
Pralidoxime iodide is a general antidote for poisoning by many insecticides. The drug is made in two steps starting with pyridine-2-carbaldehyde.(a) Show the mechanism of the reaction of
Use a Grignard reaction on an aldehyde or ketone to synthesize the following compounds:(a) Pentan-2-ol(b) 1-Phenylbutan-2-ol(c) 1-Ethylcyclohexanol(d) Diphenylmethanol
Give IUPAC names for the following carboxylic acids: (a) (d) CH3 O || CH3CHCH₂COH H H H3C C=C CH₂CH₂COH (b) (e) Br | CH3CHCH₂CH₂COH H HO₂C H (c) CO₂H CO2H CH3CH2CHCH2CH2CH3
Draw structures for the products of the following reactions: (a) CO₂H NaOCH3 ? (b) CH3 CH3CCO₂H T CH3 KOH ?
How could you convert bromobenzene into benzoic acid, C6H5CO2H?
Show how you might prepare the following esters using a Fischer esterification reaction: (a) || CH3COCH₂CH₂CH₂CH3 H₂CH₂CH (b) CH3CH₂CH₂COCH3 (c) CH3 OCHCH3
Treatment of an aldehyde or ketone with a thiol (RSH) in the presence of an acid catalyst yields a thioacetal, R'2C(SR)2. To what other reaction is this thioacetal formation analogous? Propose a
Treatment of an aldehyde or ketone with hydrazine H2NNH2, yields an azine, R2C=N-N=CR2. Propose a mechanism.
Draw structures corresponding to the following names:(a) 2,3-Dimethylhexanoic acid(b) 4-Methylpentanoic acid(c) o-Hydroxybenzoic acid(d) trans-Cyclobutane-1,2-dicarboxylic acid
Draw structures corresponding to the following names:(a) 2,2-Dimethylpropanoyl chloride(b) N-Methylbenzamide(c) 5,5-Dimethylhexanenitrile(d) tert-Butyl butanoate(e)
Rank the following compounds in order of increasing acidity:(a) Sulfuric acid, methanol, phenol, p-nitrophenol, acetic acid(b) Benzoic acid, ethanol, p-cyanobenzoic acid
Show the steps in the conversion of iodomethane to acetic acid by the nitrile hydrolysis route. Would a similar route work for the conversion of iodo benzene to benzoic acid? Explain.
What products would you obtain by treating benzoic acid with the following reagents?(a) SOCl2 (b) CH3OH, HCl (c) LiAlH4(d) NaOH
Write the steps in the mechanism of the reaction between ammonia and 2-methylpropanoyl chloride to yield 2-methylpropanamide.
Weeds derive resistance to the herbicide atrazine by a mutation in which amino acid substitution of a serine residue by a glycine occurs.(a) Identify the six codons that correspond to serine and the
What RNA base sequence is complementary to the following DNA base sequence?(5') GATTACCGTA (3')
The reduction of an amide with LiAlH4 to yield an amine occurs with both acyclic and cyclic amides (lactams). What product would you obtain from reduction of 5,5-dimethylpyrrolidin-2-one with LiAlH4?
Show the products of hydrolysis of the following esters: (a) 0 CH3 || | CH3COCHCH3 (b) CO₂CH3
How would you prepare the following ketones by reaction of a Grignard reagent and a nitrile? (a) || CH3CH2CCH2CH3 (b) O₂N CH3
Show the enolate ions you would obtain by deprotonation of the following carbonyl compounds: (a) 0 CH3CH₂CH₂CH (b) 0 CH3CCH₂CH3 (c) 0 CH3
Show how you might prepare pent-1-en-3-one from pentan-3-one: CH3CH₂CCH₂CH3 Pentan-3-one CH3CH₂CCH=CH₂ Pent-1-en-3-one
Show the product of the aldol reaction of the following compounds: (a) CH3CH₂CH₂CH سلمة (b) CH3 (c) O
What aldehydes or ketones might the following enones have been prepared from by aldol reaction? (a) (b)
What amines would react with what acid chlorides to give the following amide products?(a) CH3CH2CONH2(b) (CH3)2CHCH2CONHCH3(c) N,N-Dimethylpropanamide(d) N,N-Diethylbenzamide
Kevlar, a nylon polymer used in bulletproof vests, is made by reaction of benzene-1,4-dicarboxylic acid with benzene-1,4 diamine. Show the structure of Kevlar.
2-Methylcyclohexanone can form two enol tautomers. Show the structures of both.
Identify all acidic hydrogens in the following molecules:(a) CH3CH2CHO(b) (CH3)3CCOCH3(c) CH3CO2H(d) CH3CH2CH2CqN(e) Cyclohexane-1,3-dione
Which of the following compounds can undergo the aldol reaction, and which cannot? Explain.(a) 2,2-Dimethylcyclohexanone(b) Benzaldehyde(c) 2,2,6,6-Tetramethylcyclohexanone(d) Formaldehyde
Aldol condensation of butan-2-one leads to a mixture of two enones (ignoring double-bond stereochemistry). Draw them.
Nonconjugated β, γ-unsaturated ketones such as cyclohex-3-enone are in an acid-catalyzed equilibrium with their conjugated α, β-unsaturated isomers. Propose a mechanism for the acid-catalyzed
Write resonance structures for the following anions: (a) 0 0 |||| CH3CCHCCH3 (d) N=CCHCO₂C₂H5 (b) : CH₂C=N (c) = || CH₂CH=CHCHCCH3
Classify each of the following compounds as either a primary, secondary, or tertiary amine: (a) CH3 CH3CH2CHNH2 (b) N-H (c) -N CH3 CH3
Propose structures for amides that might be precursors of the following amines: (a) CH3CH₂CH₂NH2 (b) NH(CH2CH2CH3)2 (c) CH₂NH2
Propose structures for nitriles that might be precursors of the following amines: (a) CH3 T CH3CHCH₂CH₂NH₂ (b) Benzylamine, C6H5CH2NH2
The α, β to β, γ interconversion of unsaturated ketones is catalyzed by base as well as by acid. Propose a mechanism.Problem 11.29Nonconjugated β, γ-unsaturated ketones such as
The five-membered heterocycle imidazole contains two nitrogen atoms, one “pyrrole-like” and one “pyridine-like.” Draw an orbital picture of imidazole, and indicate the orbital in which each
Why do you suppose pentane-2,4-dione is 76% enolized at equilibrium although acetone is enolized only to the extent of about 0.0001%?
How could you synthesize the following amines from benzene? More than one step is required in each case. (a) H₂N. CO₂H (b) Br. NH₂ Br Br
Why is an enolate ion generally more reactive than a neutral enol?
How do the mechanisms of base-catalyzed enolization and acid-catalyzed enolization differ?
Which nitrogen atom in the alkaloid tryptamine is more basic? Explain. Tryptamine NH₂
The following molecule can be prepared by reaction between a primary amine and a dihalide. Identify the two reactants, and write the reaction.
Draw structures of compounds that meet the following descriptions:(a) A secondary amine with one isopropyl group.(b) A tertiary amine with one phenyl group and one ethyl group.(c) A quaternary
How might you prepare the following amines from ammonia and any alkyl halides needed? (a) CH3CH₂CH₂CH₂CH₂CH₂NH₂ CH₂NH2 (c) (b) (CH3)4N+ I- (d) NHCH3
Show the products of the following reactions: (a) (c) CH3CH₂CH₂NH₂ CH3CH2CNH2 CH3Br 1. LiAlH4 2. H₂O ? ? (b) (d) NH₂ CEN HBr ? 1. LIAIH4 2. H₂O ?
How could you prepare the following amines from ammonia and appropriate alkyl halides?(a) Triethylamine(b) Tetramethylammonium bromide
What alkyl halide would you use to synthesize dopamine, a neurotransmitter involved in regulation of the central nervous system?
How could you prepare the following amines using reductive amination reactions? Show all precursors if more than one is possible.
Pyrrole undergoes typical electrophilic substitution reactions on the carbon next to nitrogen in the ring. What products would you expect to obtain from reaction of N-methylpyrrole with the following
There are eight isomeric amines with the formula C4H11N. Draw them, name them, and classify each as primary, secondary, or tertiary.
Mescaline, a powerful hallucinogen derived from the peyote cactus, has the systematic name 2-(3,4,5-trimethoxyphenyl)ethylamine. Draw its structure.
Propose structures for amines that fit the following descriptions:(a) A secondary arylamine(b) A 1,3,5-trisubstituted arylamine(c) An achiral quaternary ammonium salt(d) A fi ve-membered heterocyclic
How might you prepare the following amines from 1-bromobutane?(a) Butylamine(b) Dibutyl amine(c) Pentylamine
How would you prepare benzylamine, C6H5CH2NH2, from each of the following starting materials? (a) CONH2 (b) CO₂H (c)
Which compound is more basic, triethylamine or aniline? Does the following reaction proceed as written? (CH3CH₂)2NH+ CI + NH₂ NH3+ CI + (CH3CH2)2N
Furan, the oxygen-containing analog of pyrrole, is aromatic in the same way that pyrrole is. Draw an orbital picture of furan, and show how it has six electrons in its cyclic conjugated π orbitals.
Fill in the missing reagents a through f in the following scheme: CHO 0₂N a CH₂NH2 CH₂OH CH₂NHCCH3 CH₂NHCCH3 H₂N CH₂Br CH₂NHCCH3
The amino acid proline is biosynthesized from glutamate semialdehyde by the following transformation, where NADH is the biological reducing agent nicotinamide adenine dinucleotide. What is the
Tetracaine, a substance used as a spinal anesthetic, can be prepared from benzene by the following route. Show how you could accomplish each of the transformations (a) through (d).
How might you use a reductive amination to synthesize ephedrine, an amino alcohol that is widely used for the treatment of bronchial asthma? ОН 대 CHCHNHCH3 CH3 Ephedrine
How might you prepare each of the amines in Problem 12.32 from butan-1-ol?Problem 12.32How might you prepare the following amines from 1-bromobutane?(a) Butylamine(b) Dibutyl amine(c) Pentylamine
The anti-inflammatory drug celecoxib, marketed as Celebrex, is widely used for treatment of rheumatoid arthritis. Draw a mechanism for the following step used in celecoxib synthesis.
How might you prepare pentylamine from the following starting materials?(a) Pentanamide (b) Pentanenitrile (c) Pentanoic acid
Which compound is more basic, CH3CH2NH2 or CF3CH2NH2? Explain.
Paraquat, a broad-spectrum weed killer, is prepared using the following step. What is the structure of paraquat? N₁ N + 2 CH3I Paraquat
Which compound is more basic, p-aminobenzaldehyde or aniline?
Suppose you were given a mixture of toluene, aniline, and phenol. Describe how you would separate the mixture into its three pure components.
Would you expect diphenylamine to be more basic or less basic than aniline? Explain.
Hexane-1,6-diamine, one of the starting materials used for the manufacture of nylon 66, can be synthesized by a route that begins with the addition of Cl2 to buta-1,3-diene. How would you carry out
Another method for making hexane-1,6-diamine (see Problem 12.41) starts from adipic acid (hexanedioic acid). How would you carry out the synthesis?Problem 12.41Hexane-1,6-diamine, one of the starting
Which of the following compounds show UV absorptions in the range 200 to 400 nm? (a) (d) Br CH3 (b) (c) (e) H₂C=CHCOCH3 (f) XX CH3 CH3
How can you explain the observation that p-nitroaniline is less basic than aniline by a factor of 40,000?
Where in the infrared spectrum would you expect each of the following compounds to absorb? (a) (b) (C)
In light of your answer to Problem 12.47, which would you expect to be more basic, aniline or p-methoxyaniline? Explain.Problem 12.47How can you explain the observation that p-nitroaniline is less
How many peaks would you expect in the 13C NMR spectra of the following compounds? (a) (d) (b) H₂C. CH3 (e) CH3 (c) (f) H3C H₂C CH3 CH3 CH₂CH3 CH3
How many absorptions would you expect the following compound to have in its 13C NMR spectrum?
Propanil, marketed under names such as Stampede and Chem-Rice, is commonly used to prevent weeds in rice fields. How would you prepare propanil from 3,4-dichloroaniline? Show the mechanism of your
Oxidation of butan-1-ol to give butanal gives a by-product whose mass spectrum shows peaks at m/z = 88 and m/z = 72. What do you think the impurity might be?
What is the concentration of cytosine, a constituent of nucleic acids, if its molar absorptivity is 6.1 x 103 L /(mol · cm) and its absorbance is 0.20 in a cell with a 1.0 cm pathlength?
How can you distinguish between hexa-1,3-diene and hexa-1,3,5-triene by UV spectroscopy?
NMR spectroscopy uses electromagnetic radiation with a frequency of 1x108 Hz. Is this a greater or lesser amount of energy than that used by IR spectroscopy?
How many absorptions would you expect each of the following compounds to show in its 1H and 13C NMR spectra?(a) Methane(b) Ethane(c) Propane(d) Cyclohexane(e) Dimethyl ether(f) Benzene(g)
The following 1H NMR resonances were recorded on a spectrometer operating at 300 MHz. Convert each into units.(a) CHCl3, 2180 Hz(b) CH3Cl, 915 Hz(c) CH3OH, 1040 Hz(d) CH2Cl2, 1590 Hz
The male sex hormone testosterone contains only C, H, and O and has a mass of 288.2089 amu, as determined by high-resolution mass spectrometry. What is the likely molecular formula of testosterone?
Tell what is meant by each of the following terms:(a) Chemical shift(b) Coupling constant(c) Max(d) Spin–spin splitting(e) Wavenumber(f) Applied magnetic field
The energy of electromagnetic radiation in units of kJ/mol, can be determined by the formula E = (1.20 x 10-4 kJ/mol)/λ, where λ is the wavelength in meters. What is the energy of infrared

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