Organic Chemistry Leroy Wade Test bank

Organic Chemistry, 7e (Wade) Chapter 11 Reactions of Alcohols 1) Classify the reaction below as an oxidation, a reduction, or neither. (CH3)2CHCH2OH → (CH3)2CHCHO A) oxidation B) reduction C) neither Answer: A Diff: 1 Section: 11.1 2) Classify the reaction below as an oxidation, a reduction, or neither. PhCO2H → PhCH2OH A) oxidation B) reduction C) neither Answer: B Diff: 1 Section: 11.1 3) Classify the reaction below as an oxidation, a reduction, or neither. cis-pent-2-ene → pentane A) oxidation B) reduction C) neither Answer: B Diff: 1 Section: 11.1 4) Which of the following reagents is not typically viewed as an oxidizing agent? A) Cl2 B) KMnO4 C) O2 D) KCl E) H2O2 Answer: D Diff: 2 Section: 11.1

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5) Which of the following compounds has carbon in the highest oxidation state? A) CO2 B) CH3C(O)CH3 C) CH3CH2OH D) CH3C(OCH2CH3)3 Answer: A Diff: 2 Section: 11.1 6) In the chromic acid oxidation of alcohols, the chromium is: A) oxidized from Cr+3 to Cr+6. B) reduced from Cr+6 to Cr+3. C) oxidized from Cr+6 to Cr+3. D) reduced from Cr+3 to Cr+6. E) none of the above Answer: B Diff: 1 Section: 11.2 7) Which of the following alcohols will give a positive chromic acid test? A) tert-butanol B) cyclohexanol C) pentan-3-ol D) both A and B E) both B and C Answer: E Diff: 2 Section: 11.2 8) Which of the following reagents is the best choice for oxidizing a primary alcohol to an aldehyde? A) H2CrO4 B) pyridinium chlorochromate C) Na2Cr2O7, H2SO4 D) KMnO4 E) LiAlH4 Answer: B Diff: 2 Section: 11.2

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9) Which alcohol reacts most rapidly with the Lucas reagent? A) benzyl alcohol B) methanol C) 2-propanol D) isobutanol Answer: A Diff: 2 Section: 11.2 10) Provide the structure of the major organic product in the reaction below.

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Diff: 2 Section: 11.2 11) Provide the structure of the major organic product in the reaction below.

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Diff: 2 Section: 11.2 12) Provide the structure of the major organic product in the reaction below.

Answer: No reaction. Tertiary alcohols are not oxidized by PCC. Diff: 2 Section: 11.2 13) Provide the structure of the major organic product in the reaction below. Na 2Cr2O7 → H 2SO4 Answer: (CH3)3CCH2CO2H Diff: 2 Section: 11.2 (CH3)3CCH2CH2OH

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14) Provide the structure of the major organic product in the reaction below.

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Diff: 2 Section: 11.2 15) Chromic acid oxidations are believed to proceed through a chromate ester intermediate. In the oxidation of propran-1-ol, provide the structure of this ester and give the mechanism for its conversion to the intermediate aldehyde. Answer:

Diff: 2 Section: 11.2 16) Provide the major organic product of the following reaction.

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Diff: 2 Section: 11.2

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17) Provide the major organic product of the following reaction.

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Diff: 2 Section: 11.2 18) Provide the reagents necessary to carry out the multistep synthesis shown below.

Answer: 1. H2SO4, Δ 2. BH3∙THF 3. H2O2, NaOH 4. PCC Diff: 2 Section: 11.2 19) Provide the structure of the major organic product that results when 3-hexanol is treated with sodium dichromate. Answer: CH3CH2COCH2CH2CH3 Diff: 2 Section: 11.2 20) Provide the structure of the major organic product that results when 1-octanol is treated with pyridinium chlorochromate. Answer: CH3(CH2)6CHO Diff: 2 Section: 11.2 21) Provide the name of the major organic product that results when trans-4-methylcyclohexanol is treated with Lucas reagent. Answer: a mixture of trans- and cis-1-chloro-4-methylcyclohexanes Diff: 2 Section: 11.2 5

22) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.2 23) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.2 24) What series of synthetic steps could be used to carry out the transformation shown below?

Answer: 1. BH3 2. H2O2, -OH 3. PCC Diff: 1 Section: 11.2 25) What series of synthetic steps could be used to prepare hexan-3-ol from propan-1-ol? Answer: 1. PCC 2. CH3CH2CH2MgBr 3. H3O+ or 1. HBr or PBr3 2. Mg, Et2O 3. CH3CH2CHO Diff: 2 Section: 11.2 6

26) What series of synthetic steps could be used to prepare PhCH(OH)CH2CH3 from PhCH2OH? Answer: 1. PCC 2. CH3CH2MgBr 3. H3O+ Diff: 2 Section: 11.2 27) What series of synthetic steps could be used to carry out the transformation shown below?

Answer: 1. PBr3 or HBr 2. Mg, ether 3. CH3CH2CHO 4. H3O+ 5. PCC or Na2Cr2O7 or KMnO4 Diff: 2 Section: 11.2 28) What series of synthetic steps could be used to carry out the transformation shown below?

Answer: 1. Cl2, hν 2. NaOEt, heat 3. BH3 4. H2O2, -OH 5. PCC 6. CH3MgBr 7. H2SO4, heat Diff: 2 Section: 11.2 29) Name the product which results when 1-methylcyclohexanol is treated with PCC. Answer: No reaction occurs; Tertiary alcohols are resistant to mild oxidation conditions. Diff: 2 Section: 11.2

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30) Describe the composition of the Jones reagent. Answer: Jones reagent is a dilute solution of chromic acid in acetone. Diff: 2 Section: 11.2 31) What series of synthetic steps could be used to prepare 1-methylcyclohexanol from cyclohexene? Answer: 1. H2O, H+ or BH3; H2O2, -OH or Hg(OAc)2, H2O; NaBH4 2. Na2Cr2O7, H+ or PCC or KMnO4 3. CH3MgI 4. H3O+ Diff: 3 Section: 11.2 32) What series of synthetic steps could be used to prepare (CH3)2CHCHO from (CH3)3CH? Answer: 1. Br2, hν 2. NaOEt, heat 3. BH3 4. H2O2, -OH 5. PCC Diff: 3 Section: 11.2 33) Which of the following catalysts is commonly used in industry to dehydrogenate alcohols? A) CuO B) Na C) NaBH4 D) (CH3)2S E) Zn Answer: A Diff: 2 Section: 11.3 34) Which of the following oxidants will convert a primary alcohol to an aldehyde? 1) sodium dichromate /sulfuric acid 3) pyridinium chlorochromate 2) copper oxide 4) dimethylsulfoxide, oxalyl chloride A) 3 and 4 B) 2, 3, and 4 C) 3 D) 1, 2, 3, and 4 E) none of the above Answer: B Diff: 3 Section: 11.3 8

35) Provide the structure of the major organic product in the reaction below.

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Diff: 2 Section: 11.3 36) Provide the major organic product of the following reaction.

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Diff: 2 Section: 11.3 37) The enzyme, alcohol dehydrogenase, which is produced by the liver, converts ethanol to __________, a normal body metabolite. Answer: acetic acid Diff: 2 Section: 11.4 38) Poisonings by methanol and ethylene glycol are relatively common. How are these poisonings treated clinically? Answer: The enzyme alcohol dehydrogenase converts these compounds to toxic substances in the body. If the patient receives intravenous infusions of ethanol, then the ethanol swamps the enzyme and the potentially deadly alcohols pass from the body unoxidized. Diff: 3 Section: 11.4 39) When (R)-butan-2-ol is treated with TsCl in pyridine, the product formed is: A) a single enantiomer. B) a racemic mixture. C) a mixture of diastereomers. D) an achial compound. E) none of the above. Answer: A Diff: 2 Section: 11.5 9

40) What compound is produced when (R)-pentan-2-ol is treated with TsCl followed by NaI? A) sodium (R)-pent-3-oxide B) sodium (S)-pent-2-oxide C) (R)-2-iodopentane D) (S)-2-iodopentane E) none of the above Answer: D Diff: 2 Section: 11.5 41) Provide the structure of the major organic product which results when ethyl tosylate is reacted with potassium t-butoxide. Answer: CH3CH2OC(CH3)3 Diff: 2 Section: 11.5 42) Provide the major organic product of the following reaction.

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Diff: 2 Section: 11.5 43) Provide the name of the major organic product that results when cyclopentanol is subjected to the following sequence of reactions: 1. TsCl, pyridine; 2. LiAlH4. Answer: cyclopentane Diff: 2 Section: 11.5 44) Provide the name of the major organic product that results when (R)-2-butyl tosylate is treated with sodium iodide. Answer: (S)-2-iodobutane Diff: 2 Section: 11.5

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45) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.5 46) Provide the necessary reagents for the following conversion.

Answer: 1) TsCl, pyridine Diff: 3 Section: 11.5

2) LiAlD4

47) Draw the tosylate ion and explain why it is a particularly good leaving group. Answer: Extensive resonance stabilization of this ion makes it a particularly good leaving group.

Diff: 2 Section: 11.5 48) Why are alcohols unreactive toward nucleophilic substitution reactions? Answer: The hydroxide ion, a relatively strong base, is a very poor leaving group. Diff: 2 Section: 11.5 49) How can the electrophilicity of hydroxyls be increased? Suggest several specific ways. Answer: The key is to convert the hydroxyl group into a better leaving group. Methods to do this include protonation, conversion to the tosylate ester, and conversion to the halide. Diff: 2 Section: 11.5

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50) Provide the structure of the major organic product in the reaction below. 1. TsCl, pyridine → 2. NaCN, acetone Answer: PhCH2CH2CN Diff: 2 Section: 11.5 PhCH2CH2OH

51) Provide the structure of the major organic product in the reaction below.

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Diff: 2 Section: 11.5 52) Which of the following reactions or series of reactions would reduce 3-metylbutan-2-ol into 3-methylbutane? A) 1. TsCl/pyridine 2. conc. KMnO4 B) 1. NaOCH3 2.. H2SO4/heat C) 1. pyridinium chlorochromate 2. ZnCl2/HCl D) 1. ZnCl2/HCl 2. t-butoxide/t-butanol E) 1. TsCl/pyridine 2. LiAlH4 Answer: E Diff: 2 Section: 11.6 53) Provide the structure of the major organic product in the reaction below. (CH3)2CHCH2OH Answer: (CH3)2CHCH2O- Na+ Diff: 2 Section: 11.6

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54) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.6 55) Which of the following alcohols will react most rapidly with the Lucas reagent (HCl, ZnCl2)? A) (CH3)3COH B) CH3CH2CH2CH2OH C) CH3CH(OH)CH2CH3 D) (CH3)2CHCH2OH Answer: A Diff: 2 Section: 11.7 56) Through what basic mechanism is 1-methylcyclohexanol converted to 1-bromo-1methylcyclohexane upon treatment with HBr? A) SN1 B) SN2 C) E1 D) E2 E) radical chain Answer: A Diff: 2 Section: 11.7 57) Provide the structure of the major organic product in the reaction below.

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Diff: 1 Section: 11.7

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58) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.7 59) Predict the major product of the reaction below and provide a stepwise mechanism which accounts for its formation. (CH3)3CCH2OH + HBr → Answer:

Diff: 3 Section: 11.7 60) Provide the structure of the major organic product in the reaction below.

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Diff: 3 Section: 11.7

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61) Predict the major product of the reaction below and provide a stepwise mechanism which accounts for its formation. CH3(CH2)6CH2OH + HBr → Answer:

Diff: 2 Section: 11.7 62) It is necessary to add ZnCl2 to promote the reaction of HCl with some alcohols while these same alcohols react with HBr quite readily. Explain. Answer: Cl- is a weaker nucleophile than is Br-. The Lewis acid ZnCl2 coordinates with the oxygen of the alcohol to increase its electrophilicity and make it a better leaving group. Diff: 2 Section: 11.7 63) What compound results when 1-butanol is treated with P/I2? A) CH3CH2CH2CH2I B) racemic CH3CH2CHICH3 C) CH3CH2CH2CH2OP(OH)2 D) CH3CH2CH2CH2PI2 E) Primary alcohols don't react with P/I2. Answer: A Diff: 1 Section: 11.8 64) Identify the sequence of reactions that successfully completes the following transformation.

A) 1) BH3 2) H2O2 / NaOH 3) P, I2 B) HI / hν C) 1) HBr / hν 2) NaI, acetone D) A and C E) all of the above Answer: D Diff: 3 Section: 11.8

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65) Provide the structure of the major organic product in the reaction below.

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Diff: 2 Section: 11.8 66) Provide the structure of the major organic product in the reaction below. (CH3)2CHCH2OH Answer: (CH3)2CHCH2Br Diff: 2 Section: 11.8 67) Provide the structure of the major organic product that results when 4-methyl-1-pentanol is treated with PBr3. Answer: (CH3)2CHCH2CH2CH2Br Diff: 2 Section: 11.8 68) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.8

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69) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.8 70) What series of synthetic steps could be used to prepare 1-bromopentane from 1bromopropane? Answer: 1. Mg, ether 2. ethylene oxide 3. HBr or PBr3 Diff: 2 Section: 11.8 71) What series of synthetic steps could be used to carry out the transformation shown below?

Answer: 1. HBr, ROOR 2. NaCN or 1. BH3 2. H2O2, -OH 3. HBr or PBr3 4. NaCN Diff: 2 Section: 11.8

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72) Which set of reagents will best convert 2,2-dimethylpropan-1-ol (neopentyl alcohol) to 4,4dimethylpentan-2-ol? A) 1. HCl 2. Mg 3. CH3CHO 4. H3O+ B) 1. HCl, ZnCl2 2. Mg 3. CH2O 4. H3O+ C) 1. SOCl2 2. Mg 3. CH3CHO 4. H3O+ D) 1. HCl, ZnCl2 2. Mg 3. CH3CHO 4. H3O+ Answer: C Diff: 2 Section: 11.9 73) Given a sample of (R)-2,3-dimethylhexan-3-ol, which of the following would be the best synthesis of (R)-3-chloro-2,3-dimethylhexane? A) HCl/ZnCl2 B) PCl3 C) SOCl2 D) 1. TsCl/Pyridine 2. NaCl E) none of the above Answer: C Diff: 2 Section: 11.9 74) Provide the structure of the major organic product in the reaction below. PhCH2(OH)CH3 Answer: PhCH2CHClCH3 Diff: 1 Section: 11.9

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75) Provide the name of the major organic product that results when trans-4-methylcyclohexanol is treated with thionyl chloride. Answer: cis-1-chloro-4-methylcyclohexane Diff: 2 Section: 11.9 76) With close attention to stereochemistry, provide the major organic product for the reaction shown below.

Answer: Diff: 2 Section: 11.9 77) Which of the following reagents can be used to convert cyclopentanol to cyclopentane? A) TsCl, pyridine followed by LiAlH4 B) Na2Cr2O7, H2SO4 C) NaBH4 followed by H3O+ D) H2SO4, heat followed by H2, Pt E) both A and D Answer: E Diff: 2 Section: 11.10 78) Which of the following alcohols undergoes dehydration upon heating with concentrated H2SO4 without carbocation rearrangement? A) 2-methylhexan-3-ol B) 3-methylpentan-3-ol C) 3,3-dimethylpentan-2-ol D) 2-methyl-2-phenylpropan-1-ol E) both A and B Answer: B Diff: 2 Section: 11.10

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79) Which of the following reaction series will result in the formation of a new secondary (2°) alcohol from the beginning alcohol listed at the top? A) Ethanol 1. Na° 2. CH3CH2I B) t-butyl alcohol 1. K2Cr3O7/acetic acid 2. CH3-MgBr 3. H3O+ C) 2-propanol 1. K2Cr3O7/acetic acid 2. CH3-MgBr 3. H3O+ D) n-butanol 1. H2SO4/heat 2. Hg(Ac)2 (aq) 3. NaBH4/alkalne E) 2-methylcycloxexanol 1. H2SO4/heat 2. OsO4/H2O2 3. H2SO4/heat Answer: D Diff: 3 Section: 11.10 80) Provide the structure of the major organic product in the reaction below.

Answer: Diff: 1 Section: 11.10 81) Provide the structure of the major organic product in the reaction below.

Answer: Diff: 2 Section: 11.10 20

82) Provide the major organic product of the following reaction.

Answer: Diff: 2 Section: 11.10 83) Provide the name of the major organic product that results when (R)-2-methyl-3-pentanol is heated with conc. H2SO4.. Answer: 2-methyl-2-pentene Diff: 3 Section: 11.10 84) Which undergoes dehydration using concentrated H2SO4 faster, cyclopentanol or 1methylcyclopentanol? Explain briefly. Answer: 1-methylcyclopentanol; goes via the more stable 3° carbocation Diff: 2 Section: 11.10 85) What is Zaitsev's rule? Answer: When the product distribution of a series of isomeric alkenes is governed by their thermodynamic stabilities, the most substituted isomer will predominate. Diff: 2 Section: 11.10 86) Dimethyl ether (CH3OCH3) can be prepared by heating methanol in concentrated H2SO4. Provide a detailed, stepwise mechanism for this process. Answer:

Diff: 2 Section: 11.10

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87) When an alcohol is heated in concentrated H2SO4, dehydration to produce both alkenes and ethers is possible. Which process is more favored by higher reaction temperatures and why? Answer: Elimination to produce alkenes is favored by higher temperatures. The ΔS for this process is more positive than is the case for the ether formation. This results in a more favorable -TΔS term, making ΔG for the elimination reaction more negative. Diff: 3 Section: 11.10 88) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.11 89) Predict the outcome of the following reaction.

Answer: Diff: 3 Section: 11.11

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90) Predict the major product of the following dehydration reaction.

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This is a pinacol rearrangement reaction where the most stable carbocation would be formed at the tertiary position in the ring. Diff: 3 Section: 11.11 91) Provide a detailed, stepwise mechanism for the reaction below.

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Diff: 3 Section: 11.11 92) What class of organic compound is the major product of the acid catalyzed reaction of an alcohol with a carboxylic acid? A) ether B) ester C) thiol D) nitrile E) sulfonate ester Answer: B Diff: 1 Section: 11.12

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93) Name the alcohol that would be used in the Fischer esterification synthesis of ethyl propanoate (CH3CH2O2CCH2CH3). Answer: ethanol Diff: 1 Section: 11.12 94) Draw the products formed in the Fischer esterification reaction between acetic acid (CH3CO2H) and cyclohexanol. Answer:

Diff: 2 Section: 11.12 95) Provide the major organic product of the following reaction.

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Diff: 2 Section: 11.12 96) Provide the name of the major organic product that results when cyclopentanol is treated with acetyl chloride. Answer: cyclopentyl acetate Diff: 3 Section: 11.12

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97) What reagents are necessary for the following conversion?

Answer: 1) Na2Cr2O7 / H2SO4 Diff: 3 Section: 11.12

2) EtOH / acid catalyst

98) Predict the outcome of the following sequence of reactions.

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Diff: 3 Section: 11.12 99) Which energetic material is a nitrate ester? A) nitroglycerin B) TNT C) RDX D) nitromethane Answer: A Diff: 2 Section: 11.13 100) What type of linkage bonds the individual nucleotides together in DNA? Answer: phosphate ester Diff: 1 Section: 11.13 101) Nitroglycerine is formed by the reaction of glycerine (propane-1,2,3-triol) and nitric acid. Provide the structure of nitroglycerine. Answer:

Diff: 1 Section: 11.13

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102) Draw the structure of dimethyl sulfate, and provide a mechanism for the reaction of this compound with sodium benzoate (PhCO2Na). Answer:

Diff: 3 Section: 11.13 103) The Williamson ether synthesis proceeds via an __________ mechanism. A) SN1 B) SN2 C) E1 D) E2 E) none of the above Answer: B Diff: 1 Section: 11.14 104) In the formation of the following ether, which reaction is preferred and why?

A) Reaction B is preferred because the oxidation step works best for primary alcohols. B) Reaction A is preferred over reaction B because the smaller methyl iodide would make a better nucleophilic target. C) Reaction A is preferred because the the formation of the carbocation would be stabilized in the benzylic position. D) Reaction B would be preferred because Iodine is a better leaving group for the SN1 reaction. E) There is no difference in these two reactions -- they would give approximately the same yields. Answer: B Diff: 3 Section: 11.14

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105) Provide the structure of the major organic product in the reaction below.

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Diff: 1 Section: 11.14 106) Show the most efficient use of the Williamson ether synthesis to prepare Answer: (CH3)2CHO-Na+ + CH3CH2CH2Br Diff: 2 Section: 11.14 107) Provide the name of the major organic product that results when cyclopentanol is subjected to the following sequence of reactions: 1. NaH; 2. CH3CH2Br. Answer: ethoxycyclopentane Diff: 2 Section: 11.14 108) Provide the major organic product of the reaction shown.

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Diff: 2 Section: 11.14

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109) What series of synthetic steps could be used to carry out the transformation shown below?

Answer: 1. Hg(OAc)2, CH3CH2OH 2. NaBH4 or 1. BH3 2. H2O2, -OH 3. Na 4. CH3CH2I Note: The hydration in the second option could be accomplished with H+, H2O or Hg(OAc)2, H2O as well. Diff: 2 Section: 11.14

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