For each of the following compounds, give the product that will be formed in an E2 reaction and indicate the configuration of the product: a. (1S,2S)-1-bromo-1,2-diphenylpropane b....
Ethylene oxide reacts readily with because of the strain in the three-membered ring. Cyclopropane has approximately the same amount of strain, but does not react with. HO-. Explan
What product is obtained when the following vicinal diol is heated in an acidic solution?
Assuming that the force constant is approximately the same for C--C, C--N, and C--O bonds, predict the relative positions of their stretching vibrations.
For each of the following pairs of compounds, identify one IR absorption band that could be used to distinguish between them: a. b. c. d. e. f. g. h. i. cis-2-butene and trans-2-butene j. CH3CH2CH2OH...
The mass spectra of 1-methoxybutane, 2-methoxybutane, and 2-methoxy-2-methylpropane are shown in Figure 13.7. Match the compounds with the spectra. 100 73 80 S 60 57 20 0 10 20 30 40 50 60 70 80 90...
Compound A, with molecular formula C4H9Cl, shows two signals in its 13C NMR spectrum. Compound B, an isomer of compound A, shows four signals, and in the proton-coupled mode, the signal farthest...
Determine the structure of each of the following compounds based on its mass, IR, and 1H NMR spectra. a. b. 100 u 50 27 114 20 40 60 80 100 120 m/z 3 2 2 28 2.9 10 13 14 15 6 6 5 2 (ppm) frequency...
What would be the major product of a Friedel-Crafts alkylation reaction using the following alkyl halides? a. CH3CH2CI b. CH3CH2CH2Cl c. CH3CH2CH(CI)CH3 d. (CH3)3CCH2Cl e. (CH3)2CHCH2Cl f. CH2=CHCH2CI
Arrange the following groups of compounds in order of decreasing reactivity toward electrophilic aromatic substitution: a. Benzene, ethylbenzene, chlorobenzene, nitrobenzene, anisole b....
Explain why hydroxide ion catalyzes the reaction of piperidine with 2,4-dinitroanisole, but has no effect on the reaction of piperidine with 1-chloro-2,4-dinitrobenzene. piperidine
What products would be obtained from the reaction of the following compounds with Na2Cr2O7 + H+ + ? a. b. c. CH-CHi CH3 CH CH CH CH3 CHCH3 CH3 CH3 (CH3)a
The intermediate shown here is formed during the hydroxide-ion-promoted hydrolysis of the ester group. Propose a mechanism for the reaction. - 213 H20 N 0 CH CH 0 N o CH3
What product would you expect to obtain from each of the following reactions? a. b. c. CH3CH2CHCH CH2CH2COH CH COCH CH HCI CH OH CH CH COH 1. SOC2 2. AICI3 3. H20
Propose a mechanism for each of the following reactions: a. b. c. H20 OCH HCI H20 OCH2CH3
Give the products of the following reactions. Show all stereoisomers that are formed. a. b. c. d. 1. (CH32CuLl 2. H30 1. CH3MgBr 2. H30 CH3 catalytic Ht CCH2CH3 + 1. LIAIH4 CH CH,CCH CH,CH2CH 2. HO
Show how each of the following compounds can be prepared from the given starting material. In each case, you will need to use a protecting group. a. b. c. CH3 CH,CHCH,CCH, CH,CHCH-COCH3 - OH OH Cl...
a. Which of the following tertiary alcohols cannot be prepared from the reaction of an ester with excess Grignard reagent? b. For those alcohols that can be prepared by the reaction of an ester with...
Explain why the product obtained in the following reactions depends on the number of equivalents of base used in the reaction: 1. CHy cHj0en CH CCH2COCH CH 2 CH3Br one equivalet CHCCHCOCH2CH 1....
Give the products of the following reactions. (Hint: See Problem 67.) a. b. Br HO CH3
a. What carboxylic acid would be formed if the malonic ester synthesis were carried out with one equivalent of malonic ester, one equivalent of 1,5-dibromopentane, and two equivalents of base? b....
Show how cyclohexylacetylene can be converted into each of the following compounds: a. b.
Show how the following compounds could be synthesized. The only carbon-containing reagents that are available for each synthesis are shown. a. b. c. CH CHCH CHCH OH CH3 CH3CHOH CH3CHCH2CH2CH3 CH3 CH3...
Propose a mechanism for the following enzyme-catalyzed reaction. (Notice that Br is attached to the more substituted carbon.) CHa CCH3 CH3 CCH3 CH chloroperoxidase CH Br pregnenolone
Rank the following compounds in order of decreasing reactivity in an electrophilic aromatic substitution reaction NHCH3 SCH3 OCH3
Organic chemists work with tetraphenylporphyrins rather than porphyrins because tetraphenylporphyrins are much more resistant to air oxidation. Tetraphenylporphyrin can be prepared by the reaction of...
a. Name an aldohexose other than D-glucose that is oxidized to D-glucaric acid by nitric acid. b. What is another name for D-glucaric acid? c. Name another pair of aldohexoses that are oxidized to...
Dithiothreitol reacts with disulfide bridges in the same way that 2-mercaptoethanol does. With dithiothreitol, however, the equilibrium lies much more to the right. Explain. HO HO SH RSSR 2 RSH HO...
a. Propose a mechanism for the formation of the prepolymer formed by bisphenol A and epichlorohydrin. b. Propose a mechanism for the reaction of the prepolymer with the hardener.
Draw the structure of the monomer or monomers used to synthesize the following polymers: a. b. c. d. e. f. g. h. For each polymer, indicate whether it is a chain-growth polymer or a step-growth...
The compound has a formal charge of (a) -1 on N (b) +2 on N (c) -1 on Al (d) +1 on Br (e) None of the above Br CH3 Br-Al-N-CH.CIH, Br CH3
For each molecule below, predict the approximate geometry about each indicated atom. Give the hybridization that explains each geometry. (a) (b) (c) (d) (e) (f) Br Br 12 HC-C-CH H C-O-CH CH H C-NH H...
Describe the hybridization of each carbon atom in each of the following structures. Base your answer on the geometry about the carbon atom. (a) CH3CI (b) CH3OH (c) CH3CH2CH3 (d) CH2 == CH2 (trigonal...
(a) On the basis of the information in Problem 38, give the likely hybridization of the orbital that contains the unshared pair of electrons (responsible for the negative charge) in each of the...
(i) Determine whether each species in the following equations is acting as a Bronsted acid or base, and label it. (ii) Indicate whether the equilibrium lies to the left or to the right, (iii)...
The compound 2-methylbutane has (a) No secondary H's (b) No tertiary H's (c) No primary H's (d) Twice as many secondary H's as tertiary H's (e) Twice as many primary H's as secondary H's
(a) What would be the major organic product of monobromination of pentane at I25C? (b) Draw Newman projections of all possible staggered conformations arising from rotation about the C2-C3 bond for...
(a) Sketch a potential energy/reaction coordinate graph showing the two propagation steps for the monobromination of pentane to give the major product (Problem 30). Use DH information from this...
Write as many structures as you can that have the formula C5H10 and contain one ring. Name them.
Which of the following cyclohexane derivatives are chiral? For the purpose of determining the chirality of a cyclic compound, the ring may generally be treated as if it were planar. CH CH1 CH3 CH3...
Label every stereocenter in the molecules in Problem 36 as R or S.
Circle each chiral molecule. Put a star (*) next to each chiral carbon and label it as R or 5. CCl CCl Br CI CH Cl CHC12 CHCl2 Br H CI H H,C CH3 Br H
Draw structural representations of each of the following molecules. Be sure that your structure clearly shows the configuration at each stereocenter. (a) (R)-3-bromo-3-methylhexane; (b)...
For each of the following questions, assume that all measurements are made in 10-cm polarimeter sample containers, (a) A 10-mL solution of 0.4 g of optically active 2-butanol in water displays an...
The molecule in the margin is menthol, with the stereochemistry omitted, (a) Identify all stereocenters in menthol, (b) How many stereoisomers exist for the menthol structure? (c) Draw all the...
For each of the following pairs of structures, indicate whether the two compounds are identical or enantiomers of each other. CH2CH3 CH2CH3 CH3 and (b) H Cl and CH-CH, Cl Cl CH3 OCH3 NH2 (c) Cl CH3...
Draw all possible products of the chlorination of (S)-2-bromo-l,l-dimethylcyclobutane. Specify whether they are chiral or achiral, whether they are formed in equal or unequal amounts, and which are...
Give the product of each of the following substitution reactions. Which of these transformations should proceed faster in a polar, aprotic solvent (such as acetone or DMSO) than in a polar, protic...
Propose a stereocontrolled synthesis of cis-l-acetoxy-3-methylcyclopentane (margin), starting from trans-1 -chloro-3-methylcyclopentane.
Write all possible El products of each reaction in Problem 25.
Predict the major product(s) and mechanism(s) for reaction between 2-bromobutane (sec-butyl bromide) and each of the reagents in Problem 42. (a) KCl in DMF (b) KI in DMF (c) KC1 in CH3NO2 (d) NH3 in...
Formulate the structure of the most likely product of the following reaction of 4-chloro-4-methyl-1-pentanol in neutral polar solution. Cl (CHJ2CCH-CH-CH-OH- HCl C6H12 +
The compound below is an example of a methyl ester. Methyl esters react with lithium iodide to give lithium carboxylate salts. The solvent in this example is pyridine (margin). Suggest several...
Ethers containing the 1,1-dimethylethyl (tert-butyl) group are readily cleaved with dilute, strong acid, as shown in the example below. Suggest a plausible mechanism for this process. What role might...
[(l-Bromo-l-methyl)ethyl]benzene, shown in the margin, undergoes solvohsis in a unimolecular, strictly first-order process. The reaction rate for [RBr] = 0.1 M RBr in 9:1 acetone: water is measured...
Give the mechanism and major product for the reaction of a secondary haloalkane in a polar aprotic solvent with the following nucleophiles. The pKa value of the conjugate acid of the nucleophile is...
The reaction is an example of which of the following processes? (a) El (b) E2 (c) SN1 (d) SN2 H,C CH,O ..
In this chapter we have encountered many examples of SN1 solvolysis reactions, all of which proceed according to the following scheme: Upon mixing the colorless substrate and solvent, a...
Draw the structures of the following alcohols, (a) 2-(Trimethylsilyl) ethanol; (b) 1-methylcyclopropanol: (c) 3-( l-methylethyl)-2-hexanol; (d) (R)-2-pentanol; (e) 3,3-dibromocyclohexanol.
Rank the compounds in each group in order of decreasing acidity. (a) CH3CHCICH20H, CH3CHBrCH2OH, BrCH2CH2CH2OH (b) CH3CH2CH2OH, CCI3CH2OH, (CH3)2CC1CH2OH (c) (CH3)2CHOH, (CF3)2CHOH, (CC13)2CHOH
What is the direction of the following equilibrium? H- + H2O H2 + HO-
The common practice of washing laboratory glassware with acetone can lead to unintended consequences. For example, a student plans to carry out the preparation of methylmagnesium iodide, CH3MgI,...
Cortisone is an important steroidal anti-inflammatory agent. Cortisone can be synthesized efficiently from the alkene shown here. Of the following three chlorinated compounds, two give reasonable...
The reaction of two equivalents of Mg with 1, 4-dibromobutane produces compound A. The reaction of A with two equivalents of CH3CHO (acetaldehyde). followed by work-up with dilu aqueous acid,...
Suggest the best synthetic route to each of the following simple alcohols, using in each case simple alkane as your initial starting molecule. What are sonic disadvantages of beginning sy theses with...
On which side of the equation do you expect each of the following equilibria to lie (left or right)? (a) (CH3)3 COH + K-OH- (CH3)3 CO-K+ + H2O. (b) CH3OH + NH3 CH3O- + NH-4; (pKa = 9.2). (c) (d) NH3...
Evaluate each of the following possible alcohol syntheses as being good (the desired alcohol is the major or only product), not so good (the desired alcohol is a minor product), or worthless. (a) (b)...
(a) What would be the product of reaction of rrans-2-bromocyclooctanol (margin) with NaOH? (b) Compare the effect of entropy on the transition state of this reaction with its effect in the reactions...
Give the expected major product of reaction of 2,2-dimethyloxacyclopropane with each of the following reagents? (a) Dilute H2SO4 in CH3OH (b) Na+ -OCH3 in CH3OH (c) Dilute, aqueous HBr (d)...
Write out a mechanism for every reaction depicted in Problem 38. (a) (b) (c) O .LiAID 2. H, H,O CH3CH O 1.LIAIH 2D D.O LiAID CH,CH>
Which of the following halogenated compounds can be used successfully to prepare a Grignard reagent for alcohol synthesis by subsequent reaction with an aldehyde or ketone? Which ones cannot and why?...
Give the structures of compounds A, B, and C (with stereochemistry) from the information in the following scheme? 2 CH,SO CI, (CH,CH2N, CH2CI Na2S, H2O, DM Excess H-O H20 C,Hi,s,06 C,Hi,s CH1402
Give the major products of each of the following reactions (after aqueous work-up). The solvent in each case is ethoxyethane (diethyl ether). (a) (b) (c) (d) (e) MgBr+CH CH3 CH,CHCH,MgCl + CH3CH-...
For each reaction presented in Problem 43. write out the complete, step-by-step mechanism using curved-arrow notation. Include the aqueous acid work-up. (a) (b) (c) (d) (e) MgBr+CH CH3 CH,CHCH,MgCl +...
Write the structures of the products of reaction of ethylmagnesium bromide, CH3CH2MgBr, with each of the following carbonyl compounds. Identify any reaction that gives more than one stereoisomeric...
Compare the following methods of alkene synthesis from a general primary alcohol. State the advantages and disadvantages of each one. RCH2CH2OH K OC(CH,) RCH,CH-Br RCH=CH,
If the NMR spectra of the molecules in Problem 30 were recorded by using high resolution for each nucleus, what differences would be observed?
Give the expected major product of each of the following reactions. PCC is the abbreviation for pyridinium chlorochromate (Section 8-6). (a) (b) (c) (d) (e) CH CH CH,OH NeCrO HSO, HO PCC, CH,CI (CH3)...
Give the expected major product of each of the following reaction sequences. PCC refers to pyridinium chlorochromate. (a) (b) (c) 1. CrO, H,SO., HO 2. CH.CHMgBr, (CH,CH, 3. H, H,O CHs) CHOH 1. OH,...
Unlike Grignard and organolithium reagents, organometallic compounds of the most electropositive metals (Na, K, etc.) react rapidly with haloalkanes. As a result, attempts to convert RX into RNa or...
The 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...
(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...
List the four important features of 1H NMR and the information you can derive from them.
Suggest three different syntheses of 2-methyl-2-hexanol. Each route should utilize one of the following starting materials. Then use any number of steps and any other reagents needed. (a) (b) (c) H
The reduced form of the coenzyme nicotinamide adenine dinucleotide (NAD+, Chemical Highlight 8-1) is abbreviated NADH. In the presence of a variety of enzyme catalysts, it acts as a biological...
The 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,...
The 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)...
In this transformation, what is the best structure for "A"? (a) (b) (c) (d) , 1. LiAlH, dry ether 2. H., H,O (work-up) CH-CH CH2CH CH2CH3 CH2CH -, - -,
Give the expected major product of each of the following reactions. (a) (b) (c) (d) CH CH,CH,OH COnC HI Conc. HBr (CH,)CHCH.CH.OH- Conc. HI OH CH,CH2,COH COn HCT
Give reasonable products for each of the following reactions. (a) (b) (c) (d) (e) (f) One equivalent Na2S CICH2CH2CH2CH2C Br KSH CH3 KSH CH3CH2 CH,SH CH3CH2 SH Excess H202
Order 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) (e)...
Match 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...
Assign as many peaks as you can in the mass spectrum of 1-bromopropane (Figure 11-24).
What is the degree of un-saturation in cyclobutane? (a) Zero (b) One (c) Two (d) Three
Give the products of bimolecular elimination from each of the following isomeric halogenated compounds. a. b. One of these compounds undergoes elimination 50 times faster than the other. Which...
You 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...
Hectane is the IUPAC name for the unbranched alkane that contains 100 carbon atoms. (a) How many _ bonds are there in hectane? (b) How many alkanes have names of the type x-methylhectane? (c) How...
Sketch an approximate potential energy diagram similar to that shown in Figures 3.4 and 3.7 for rotation about the carboncarbon bond in 2,2-dimethylpropane. Does the form of the potential energy...
The constitutional isomer of ethanol, dimethyl ether (CH3OCH3), is a gas at room temperature. Suggest an explanation for this observation.
Of the isomeric C5H11+ carbocations, which one is the most stable?