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11_all_

Course Number: CHEM 101, Spring 2010

College/University: Duke

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11.1 What is wrong with the use of such names as isopropanol and tert-butanol? Answer: We should say them as isopropyl alcohol and tert-butyl alcohol. 11.2 Give bond-line formulas and appropriate names for all of the alcohols and ethers with the formulas (a) C3H8OH and (b) C4H10O (a) OH CH3CH2 CH2 OH propanol (b) H3C C H CH3 CH3 OCH2CH3 Ethyl methyl ether H3C H3C H3C C OH 2-propanol OH CH3CH2CH2 CH2 OH...

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What 11.1 is wrong with the use of such names as isopropanol and tert-butanol? Answer: We should say them as isopropyl alcohol and tert-butyl alcohol. 11.2 Give bond-line formulas and appropriate names for all of the alcohols and ethers with the formulas (a) C3H8OH and (b) C4H10O (a) OH CH3CH2 CH2 OH propanol (b) H3C C H CH3 CH3 OCH2CH3 Ethyl methyl ether H3C H3C H3C C OH 2-propanol OH CH3CH2CH2 CH2 OH butanol H3C H2 C C H CH3 2-butanol tert-butyl alcohol CH3 CH3 OCH2CH2CH3 propyl methyl ether CH3CH2OCH2 CH3 diethyl ether H3C C H OCH3 isopropyl methy ether OH 2-methyl-1-propanol 11.3 1,2-Propanediol and 1,3-propanediol(propylene glycol and trimethylene glycol, respectively; see Table11.2)have higher boiling points than any of the butyl alcohols, even though all of the compounds have roughly the same molecular weight. How can you explain this observation. The diols have two OH, so it can form stronger hydrogen bonding. Therefore, 1,2-Propanediol and 1,3-propanediol have higher boiling points than any of the butyl alcohols. 11.4 What products would you expect from acid-catalyzed hydration of each of the following alkene? (a) Ethene (c)2-Methylpropene (b)Propene (d)2-Methyl-1-butene H3O (a) OH OH H3O (b) OH H 3O (c) H 3O HO (d) 11.5 Treating 3,3-dimethyl-1-butene with dilute sulfuric acid is largely unsuccessful as a method for preparing 3,3-dimethyl-2-butanol because an isomeric compound is the major product. What is this isomeric compound and how is it formed? H 3 ,3 -d im eth y l-1 -b u ten e OH 2 ,3 -D im e th y l-b u ta n -2 -o l (m ain ) 11.6 Starting with an appropriate alkene, show all steps in the synthesis of each of the following alcohols by oxymercuration-demercuration. (a) tert-Butyl alcohol (b) Isopropyl alcohol (c) 2-Methyl-2-butanol Answer: (a) (1) H g(O A c) 2 /T H F-H 2 O (2) N aB H 4 , O H tert-butyl alcohol OH (b) (1) Hg(O Ac) 2 /THF-H 2 O (2) NaBH 4 , OH HO Isopropyl alcohol (c) (1) Hg(OAc)2/THF-H2O (2) NaBH4 ,OH HO 2-Methyl2-butanol 11.7 When an alkene is treated with mercuric trifluoroacetate, Hg (O2CCF3)2, in THF containing an alcohol, ROH, the product is an (alkoxyalkyl) mercury compound. Treating this product with NaBH4/OH- results in the formation of an ether. The overall process is called solvomercuration-demercuration. RO Hg(O2CCF3 )2/THF-ROH solvomercuraton Alkene H NaBH4 ,OHdemercuraton HgO2CCF3 (Alkoxyalkyl)mercuric trifluoroacetate OR Ether a) Outline a likely mechanism for the solvomercuration step of this ether synthesis. b) Show how you would use solvomercuration-demercuration to prepare tert-butyl methyl ether. a) Step 1: O F O O F O F F Hg O F F O F O F F O F F F Hg + Step 2: O F Hg O F F Hg O F O F F Step 3: OH R R OH R OH O O F Hg O F F Hg O F F F OH O F Hg O F F Step 4(demercuration): H OH OH NaBH4, OHO F Hg O F b) The reaction is: Hg(O2 CCF3)2 /THF-CH3 OH O solvomercuraton HgO2CCF3 O F NaBH4,OHdemercuraton 11.8 Starting with an appropriate alkene, show the synthesis for (a) tributylborane, (b) triisobutylborane, and (c) tri-sec-butylborane. (d) Show the stereochemistry involved in the hydroboration of 1-methylcyclohexene. a) tributylborane B THF:BH3 b) triisobutylborane THF:BH3 B c) tri-sec-butylborane THF:BH3 B d) Hydroboration of 1-methylcyclohexene H H B B 11.9 Treating a hindered alkene such as 2-methyl-2butene with THF: BH3 lead to the formation of a dialkborane instead of a trialkylborane. When 2 mol of 2-methyl-2butene adds to 1mol of BH3, the product formed has the nicknamedisiamylborane. Write its structure. Disamylborane is a useful reagent in certain syntheses that require a sterically hindered borane. ( The name disiamyl comes fromdi-secondaryiso-amyl, a completely unsystematic and unacceptable name. The name amyl is an old common name for a five-carbon alkyl group.) The answer: H H H H B 11.10 Starting with the appropriate alkene show how you could use hydroboration oxidation to prepare each of the following alcohols. (a) 1-Pentanol (b) 2-Methyl-1-pentanol (c) 3-Methyl-2pentanol (d) 2-Methyl-3-pentanol (e) trans-2methylcyclobutanol (a) THF:BH3 (CH3CH2CH2CH2CH2)3B H2O2 NaOH OH (b) THF:BH3 (CH3CH2CH2CHCH3CH2)3B H2O2 NaOH OH OH (c) THF:BH3 H2O2 (CH3CH2CHCH3CHCH3)3B NaOH THF:BH3 (d) 3 H2O2 NaOH B OH (e) THF:BH3 CH3 H H CH3 CH3 H H CH3 H2O2 + NaOH H H OH + OH H BH2 BH2 H 11.11 Starting with any needed alkene (or cycloalkene), and assuming you have deuterioacetic acid (CH3CO2D) available, outline syntheses of the following deuterium labeled compounds. (a) (CH3)2CHCH2CH2D Answer: O D H O B THF:BH3 3 H D (b) (CH3)2CHCHDCH3 Answer: O D THF: BH3 O BH2 D CH3 (c) D (+ enantiomer) O CH3 CH3 O Answer: CH3 THF: BH3 D BH2 D (d) Assuming you also have available THF: BD3 and CH3CO2T, can you suggest a synthesis of the following? D T CH3 H (+ enantiomer) Register to View AnswerCH3 O T O D THF: BD3 H H BH2CH3 T CH3 H 11.12 Write equations for the acid-base reactions that would occur (if any) if ethanol were added to solutions to each of the following compounds. In each reaction, label the stronger acid, the stronger base, and so forth. (a) sodium amide, (b) sodium ethynide, and (c) sodium acetate (consult Table 3.1) Answer: OH OH + + Na+ Na+ -C Na+ NH2- O O Na+ Na+ + + NH3 + O NH2- Na+ -C + O NH3 + OH O Na+ O- + Na+ OH So the relative basicity of these bases: sodium amide > sodium ethynide > sodium acetate 11.13 Suggest an experiment using an isotopically labeled alcohol that would prove that the formation of an alkyl sulfonate does not cause cleavage at the CO bond of the alcohol. Solution: We can use alcohol CH3CH218OH to react with methanesulfonyl chloride. If we find that the O H3C S O 18 O OCH2CH3 H3C S O OCH2CH3 product is , and the compound is not detected. Then it will prove that the formation of alkyl sulfonate does not cause cleavage at the CO bond of the alcohol. 11.14 Starting with the appropriate sulfonic acid and PCl3, or with the appropriate sulfonyl chloride, show how you would prepare (a) methyl p-toluensulfonate, (b) isobutyl methanesulfonate, and (c) tert-butyl methanesulfonate. Solution: (a) CH 3 CH3 + CH3 OH O S Cl O O S OCH 3 O (b) O H3C S O Cl O + (CH3)2CHCH2OH H3C S O OCH2CHCH3 CH3 (c) O H3C S O Cl O + (CH3)3 COH H3C S O O C(CH3)3 11.15 Show the configurations of products formed when (a) (R)-2-butanol is converted to a tosylate, and (b) when this tosylate reacts with hydroxide ion by an SN2 reaction. (c) Converting cis-4-methylcyclohexanol to a tosylate and then allowing the tosylate to react with LiCl (in an appropriate solvent) yields trans-1-chloro-4-methylcyclohexane. Outline the stereochemistry of these steps. Answer: (a) O OH H O H O base S O Cl + (- HCl) S O (b) O S O O H O OHSN 2 S O O H + OH (c) OH OTs TsOH base Cl- Cl 11.16 (a) What factor explains the observation that tertiary alcohols react with HX faster than secondary alcohols? (b) What factor explains the observation that methanol reacts with HX faster than a primary alcohol? Answer: (a) Because they are SN1 reactions, the tertiary alcohols can lead to tertiary carbocation and it is more stable than secondary carbocation. (b) Because they are SN2 reactions, the hindrance of methyl group is smaller than a primary alcohol. 11.17 Treating 3-methyl-2-butanol (see following reaction) with HBr 2-bromo-2-methylbutane as the sole product. Outline a mechanism for the reaction. CH3 CH3 yields CH3CHCHCH3 OH 3-Methyl-2-butanol HBr CH3CCH2 CH3 Br 2-Bromo-2-methylbutane Answer: CH3 CH3 H3C CH3CHCHCH3 OH CH3CHCHCH3 + CH3CH CH3 CHCH3 rearrangement C H3C CH2CH 3 H OH2 Br T.M. 11.18 An exception to what we have just said has to do with syntheses of unsymmetrical ethers in which one alkyl group is a tert-butyl group and the other group is primary. This synthesis can be accomplished by adding tert-butyl alcohol to a mixture of the primary alcohol and H2SO4 at room temperature. Give a likely mechanism for this reaction and explain why it is successful. Answer: H R3 C O H + H OSO3H R3 C O H H R3C RH2C O H H + R 3C R3C O CH2R R3 C O CH2R + H2O R3C O CH2R 11.19: (a) Outline two methods for preparing isopropyl methyl ether by a Williamson synthesis. (b) One method gives a much better yield of the ether than the other. Explain which is the better method and why. Answer: (1) CH3 CH3 CH3CHONa (2) + CH3CH2 Br CH3CHOCHCH2 CH3 CH3CH2ONa + CH3CH CH3 Br CH3CHOCHCH2 Method (1) gives a much better yield of the ether, because the secondary carbon is more easily attacked than the tertiary carbon in method (2). 11.20 The two synthesis of 2-ethoxy-1-phenylpropane shown here give products with opposite optical rotations. C6 H5 CH2CHCH3 OH K potassium alkoxide +H2 C2H5Br -KBr C6H5CH2CHCH3 OC2H5 []=+33.0 TsCl/base(Ts=p-toluenesulfonyl) C6H5CH2CHCH3 OTs [ ]=+23.5 C2H5OH K2CO3 C6H5CH2CHCH3 OC2H5 []=-19.9 How can you explain this result? Answer: When potassium alkoxide attacks C2H5Br, the configuration of the chiral carbon is unchanged. However, when the starting material is dealt with TsCl ,the oxygen of the ethanol attacks the chiral carbon form the backside and then the OTs group leaves. Therefore the optical rotation is opposite. 11.21 Write a mechanism that explains the formation of tetrahydrofuran (THF) from the reaction of 4-chloro-1-butanol and aqueous sodium hydroxide. Answer: HO Cl O Cl O 11.22 Epoxides can be synthesized by treating halohydrins with aqueous base. For example, treating ClCH2CH2OH with aqueous sodium hydroxide yields ethylene oxide. (a) Propose a mechanism for this reaction. (b) trans-2-Chlorocyclohexanol reacts readily with sodium hydroxide to yield cyclohexene oxide. Cis-2-Chloro-cyclohexanol does not undergo this reaction, however. How can you account for this difference? Answer: Cl (a) OHCH2CH2 Cl O H2C O CH2 (b) trans-2-Chlorocyclohexanol Cl O O cis-2-Chlorocyclohexanol Backsidec attack is not possible with the cis-isomer, therefore, it doesn't form an epoxide 11.23 (a) The mechanism for the formation of the tert-butyl ether from a primary alcohol and isobutylene is similar to that discussed in Problem 11.8. Propose such a mechanism. (b) What factor makes it possible to remove the protecting tert-butyl group so easily? (Other ethers require much more forcing conditions for cleavage, as we shall see in Section 11.16.) (c) Propose a mechanism for the removal of the protecting tert-butyl group. Solution: (a) H+ H2C C CH3 CH3 RCH2OH H3C C CH3 CH3 CH3 RH2C O H C CH3 CH3 CH3 RH2 C O C CH3 CH3 H2 O (b) When the ether is protonated, because the tert-butyl cation is stable, so it is a better leaving group, it can leave easily in the dilute acid condition. (c) H+ RH2C O CH3 C CH3 CH3 CH3 RH2C O H C CH3 CH3 XRH2 C OH + CH3 +C CH3 CH3 X CH3 C CH3 CH3 11.24 When am ether is treated with cold concentrated HI, cleavage occurs as follows: ROH +RI R-O-R + HI When mixed ethers are used, the alcohol and alkyl iodide that form depend on the nature of the alkyl groups. Explain the following observations. (a) When (R)-2-methoxybutane reacts, the products are methyl iodide and (R)-2-butanol. (b) When tert-butyl methyl ether reacts, the products are methanol and tert-butyl iodide. Solution: (a) This reaction undergoes a SN2 mechanism, first (R)-2-methoxybutane protonated, because of the steric hindrance, the iodine anion attacks the methyl group, then (R)-2-butanol formed. (b) This reaction undergoes a SN1 mechanism, because tert-butyl cation can exist stably, in this reaction it leaves after that tert-butyl methyl ether protonated, and the iodine anion attaches to the cation to form tert-butyl iodide. 11.25 Propose structures for each of the following products: (a) Oxirane HA CH3OH C3H8O(an industrial solvent called Methyl Cellosolve) (b) Oxirane (c) Oxirane (d) Oxirane (e) Oxirane O HA CH3CH2 OH C4H10O2(Ethyl Cellosolve) KI H2O C2H4 IO NH3 C2H7 NO CH3ONa CH3OH C3H8O (a) O OH OH I OH H2 N OH O OH (b) (c) (d) (e) H2 C 11.26 Treating 2.2-dimethyloxirane, O C(CH3)2 , with sodium methoxide in methanol gives primarily 1-methoxy-2-methyl-2-propanol. What factor accounts for this result? Hydrolysis by base should consider the steric hindrance HOMe OMe O O O HO H 2C O C(CH3)2 11.27 When sodium ethoxide reacts with 1-(chloromethyl) oxirane, labeled with 14C as shown by the asterisk in I, the major product is an epoxide the bearing label as in II. Provide an explanation for this reaction. Cl CH2 CH *2 CH O NaOC2 H5 H2 C CH * CH 2 OCH3 O 1-(Chloromethyl)oxirane (epichlorohydrin) Solution: OC2H5 Cl CH2 CH O H2C Cl CH * CH2 O * OCH CH 2 3 H2C CH * CH2 OCH3 O 11.28 Outline a mechanism similar to the one just given that shows how the enantiomeric form of trans-1, 2-cyclopentanediol is produced. Solution: H H O H H H OH OH H H H O H H OH H H O+ H OH O H H O H H trans-1,2-cyclopentanediol 11.29 Outline a scheme such as the one shown in Fig.11.5 showing how the reaction of CH3(CH2)6CH2Cl with cyanide ion (just shown) takes place by phase-transfer catalysis. Be sure to indicate which ions are present in the organic phase, which are in the aqueous phase, and which pass from one phase to the other. Answer: Aqueous Phase CN+ CNQ+XQ+X+ CH3(CH2)6CH2CN Q+CN+ CH3(CH2)6CH2Cl Q+XCl+ Q+CN- CH3 (CH2)6 CH2 Cl Organic Phase 11.30 write structures for (a) 15-crown-5 and (b) 12-crown-4. Answer: (a) O O 15 O O O (b) O O 12 O O 11.31 Give an IUPAC substitutive name for each of the following alcohols: OH (a) (CH3 )3CCH2 CH2 OH CH3 (e) CH3 (b) (c) H2C CHCH2CHOH H HOCH2CHCH2CH2OH CH3 (f) H CH3 HO (d) C6H5CH2CH2 OH Answer: (a) 3,3-dimethylbutanol (b) 4-penten-2-ol (c) 2-methyl-butane-1, 4-diol (d) 2-phenyl-enthanol (e) 1-methyl-cyclopent-2-enol (f) cis-3-methyl-cyclohextanol 11.32 Write structural formulas for each of the following: (a) (Z)-2-Buten-1-ol (f) Tetrahydrofuran (b) (R)-1,2,4-Butanetriol (g) 2-Ethoxypentane (c) (1R,2R)-1,2-Cyclopentanediol (h) Ethyl phenyl ether (d) 1-Ethylcyclobutanol (i) Diisopropyl ether (e) 2-Chloro-3-hexyn-1-ol (j) 2-Ethoxyethanol Answer: OH OH (a) OH (b) HO HO HO HO (c) Cl (d) O (e) OH (f) O (g) O (h) O (I ) O (j) HO 11.33 Starting with each of the following, outline a practical synthesis of 1-butanol. (a) 1-Butene (b) 1-Chlorobutane (c) 2-Chlorobutane (d) 1-Butyne Answer: (a) H2 (1) THF:BH3 CH3CH2CH CH2 OH CH3CH2CH2 C (2) H2O2/NaOH (b) CH3CH2CH2 CH2Cl (c) NaOH/H2O CH3CH2CH2 C H2 OH (1)t-BuOK/t-BuOH (2)THF:BH3 CH3 CH2CHClCH3 CH3CH2CH2 (3)H2 O2/NaOH (d) H2 C OH CH3CH2C CH (1)H2 lindlar's catalyst (2)THF:BH3 (3)H2O2/NaOH CH3 CH2CH2 H2 C OH 11.34 Show how you might prepare 2-bromobutane from (c) 1-Butene (a) 2-Butanol, CH3CH2CHOHCH3 (d) 1-Butyne (b) 1-Butanol, CH3CH2CH2CH2OH Answer: (a) CH3CH2 CHOHCH3 (b) PBr3 CH3 CH2 CHBrCH3 (1)conc H2SO4 heat CH3CH2CHBrCH3 CH3CH2CH2CH2OH (2)HBr (c) CH3 CH2CH (d) CH2 HBr CH3 CH2 CHBrCH3 (1)H2 lindlar's catalyst CH3CH2C CH (2)HBr CH3 CH2 CHBrCH3 11.35 Show how you might carry out the following transformation: (a) Cyclohexanol chlorocyclohexane (b) Cyclohexene chlorocyclohexane (c) 1-Methylcyclohexene 1-bromo-1-methylcyclohexane (d) 1-Methylcyclohexene trans-2-methylcyclohexanol (e) 1-Bromo-1-methylcyclohexane cyclohexylmethanol Solution: (a) OH H2SO4 heat HCl Cl (b) HCl Cl Br (c) CH3 HBr CH3 (d) CH3 1)B2H6 2)-OH/H2O2 OH CH3 Br (e) CH3 (CH3)3 O H2 C CH2 HBr ROOR Br OH- C H2 OH 11.36 Give the structures and acceptable names for the compounds that would be formed when 1-butanol is treated with each of the following reagents: (a) Sodium hydride (b) Sodium hydride, then 1- bromopropane (c) Methanesulfonyl chloride and base (d) p-Toluenesulfonyl chloride (e) Product of (c), then sodium methoxide (f) Product of (d), then KI Solution: (g) Phosphorus trichloride (h) Thionyl chloride (i) Sulfuric acid at 140 (j) Refluxing concentrated HBr (k) tert-Butylchlorodimethylsilane (l) Product of (k), then fluoride ion (a) CH3CH2CH2CH2OH + NaH Name of the product: Sodium butoxide. CH3CH2CH2CH2ONa + H2 CH3CH2 CH2 Br CH3CH2CH2CH2OCH2 CH2CH3 O Cl (b) CH3CH2CH2 CH2 OH + NaH NaH Name of the product: Butyl propyl ether. O (c) CH3CH2CH2CH2OH + H3C S O base H3C S O O OCH2CH2CH2CH3 Name of the product: Butyl methanesulfonate. O (d)H3C S O Cl CH3(CH2)3OH H3C S O OCH2CH2CH2CH3 Name of the product: Butyl p-toluenesulfonate. O (e) H3C S O OCH2 CH2CH2CH3 + CH3ONa CH3OCH2CH2 CH2 CH3 Name of the product: Butyl methyl ether. O (f) H3C S O OCH2CH2CH2CH3 KI CH3CH2 CH2 CH2I Name of the product: 1- iodobutane. (g) CH3CH2CH2CH2OH PCl3 CH3CH2CH2CH2Cl Name of the product: 1- chlorobutane (h) CH3CH2CH2CH2 OH (i) CH3 CH2 CH2CH2OH SOCl2 CH3 CH2 CH2CH2Cl Name of the product: 1- chlorobutane H2 SO4 140 CH3CH2CH2CH2 OCH2CH2CH2CH3 Name of the product: Dibutyl ether. HBr (j) CH3CH2CH2CH2OH Refluxing CH3CH2CH2CH2Br Name of the product: 1- bromobutane. CH3 CH3 Si CH3 Cl + CH3 CH2 CH2CH2OH H3C CH3 C CH3 CH3 Si CH3 OCH2 CH2CH2CH3 (k) H3C C CH3 Name of the product: tert-Butylbutyldimethylsilyl butyl ether CH3 CH3 Si CH3 OCH2CH2CH2CH3 CH3 CH3 Si CH3 F (l) H3C C CH3 F- CH CH CH CH OH + H C 3 3 2 2 2 C CH3 Name of the product: tert-Butylfluorodimethylsilane. 11.37 Give the structures and names for the compounds that would be formed when 2-butanol is treated with each of the reagents in Problem 11.36. Answers: O CH3 OCHCH2CH3 (a) CH3CHCH2CH3 ONa (b) CH3CHOCH2CH2CH3 C 2H5 (c) H3CS O Sodium isobutoxide Isobutyl propyl ether O CH3 OCHCH2CH3 Isobutyl methanesulfonate (d) H3C S O (e) H3CO CHCH2CH3 CH3 Isobutyl p-methantoluenesulfonate (f) CH3CHCH2CH3 I Isobutyl methyl ether (h) CH3CHCH2CH3 Cl (g) CH3CHCH2CH3 Cl 2-Iodobutane (i) H3CHC CHCH3 2-Chlorobutane (j) CH3CHCH2CH3 Br 2-Chlorobutane 2-Butene CH3 2-Bromobutane (k) CH3CH2CHO CH3 Si CH3 C(CH3)3 (l) CH3CHCH2CH3 OH tert-Butylisobutoxydimethylsilane 2-Butanol 11.38 What compounds would you expect to be formed when each of the following ethers is refluxed with excess concentrated hydrobromic acid? (a) Ethyl methyl ether (c) Tetrahydrofuran (d) 1,4-Dioxane (b) tert-Butyl ethyl ether Answers: (a) CH3CH2Br and CH3Br (b) t-BuBr and CH3CH2Br 11.39 Write a mechanism that accounts for the following reaction: (c) BrCH2CH2CH2CH2Br (d) BrCH2CH2Br OH HA + HOH Answer: H+ OH OH 2 H 11.40 Show how you would utilize the hydroboration-oxidation procedure to prepare each of the following alcohols: (a) 3,3-Dimethyl-1-butanol (1)B2H6,THF (2) H2O2/OH(b) 1-Hexanol HO (1)B2 H6 ,THF (2) H2 O2/OH(c) 2-Phenylethanol HO (1)B2H6,THF (2) H2O2 /OH- OH (d) trans-2-Methylcyclopentanol H CH3 (1)B2H6,THF (2) H2O2 /OH- H CH3 HO H 11.41 Write a three-dimensional formula for the product formed when 1-mehtylcyclo-hexene is treated with each of the following reagents. In each case, designate the location of deuterium of tritium atoms. (a) (1) THF:BH3,(2)CH3CO2T (b) (1) THF:BH3,(2)CH3CO2D (c) (1)THF:BD3,(2)NaOH,H2O2,H2O Register to View Answer D (a) T (b) D (c) OH 11.42 Starting with isobutane show how each of the following could be synthesized. (You need not repeat the synthesis of a compound prepared if an earlier part of this problem.) (a) tert-Butyl bromide (b) 2-Methylpropene (c) Isobutyl bromide (d) Isobutyl iodide (e) Isobutyl alcohol (two ways) (f) tert-Butyl alcohol (g) Isobutyl methyl ether CH3 O (h) CH3CHCH2 OCCH3 CH3 (i) CH3CHCH2CN CH3 (j) CH3CHCH2SCH3 (two ways) CH3 CH3 CCH2CBr3 (k) Br Answer: Br + Br2 (a) Br Base -HBr HBr Br (b) (c) R2O2 Br NaI I (d) 1, BH3 (e) 2, OH- / H2O2 OH Br H 2O OH (f) 1. Na OH O (g) 2. CH3I OH CH3COCl Et3N O (h) O Br NaCN CN (i) Br CH3SNa S (j) BrCBr3 R2O2 (k) Br CBr3 11.43 Vicinal halo alcohols (halohydrins) can be synthesized by treating epoxides with HX. (a) Show how you would use this method to synthesize 2-chlorocyclopentanol from cyclopentene. (b) Would you expect the product to be cis-2-chlorocyclopentanol or trans-2-chlorocyclopentanol; that is , would you expect a net syn addition or a net anti addition of Cl and OH? Explain. Answer: (a) OH O R C O OH O HO HCl Cl + Cl (b) It should be trans-2-chlorocyclopentanol. 11.44 Outline below is a synthesis of the gypsy moth sex attractant E ( a type of pheromone, see Section 4.16). Give the structures of E and the intermediates A-D in the synthesis. 1-Bromo-5-methylhexane A(C H ) NaNH2 9 16 liq. NH3 liq. NH3 D(C19 H38 ) C6H5CO3 H E(C19 H38O) 1-Bromodecane B(C9 H15Na) HC CNa C(C19 H36) H2 Ni2B(P-2) Answer: HC CNa 1-Bromo-5-methylhexane HC liq. NH3 C(CH2)4CH(CH3 )2 NaNH2 NaC liq. NH3 H C(CH2)4CH(CH3)2 H 1-Bromodecane CH3(CH2)9C C(CH2)4CH(CH3)2 H2 Ni2B(P-2) H3C(H2C)9 (CH2)4CH(CH3)2 (CH2)4CH(CH3)2 H O O C6H5CO3H H H3C(H2C)9 H H3C(H2C)9 + H (CH2)4CH(CH3 )2 11.45 Starting with 2-methylpropene (isobutylene) and using any other needed reagents, outline a synthesis of each of the following: (a) (CH3)2CHCH2OH (c) (CH3)2CDCH2T (b) (CH3)2CHCH2T (d) (CH3)2CHCH2OCH2CH3 CH3 1) B2 H6 2) H2 O2,OH1. BH3 2. CH3 COOT CH3 Answer: (a) H2C CCH3 CH3 CH3CHCH2OH H2C CCH3 (CH3 )2CHCH2T (b) CH3 1. BD3 2. CH3COOT CH3 - (c) (d) H2C CCH3 (CH3)2CDCH2T CH3 H2C CCH3 1) B2 H6 2) H2O2,OH 1. NaOEt 2. EtBr (CH3)2CHOCH2CH3 CH3CHCH2OH 11.46 Show how you would use oxymercuration-demercuration to prepare each of the following alcohols from the appropriate alkene: (a) 2-Pentanol (c) 3-Methyl-3-pentanol (b) 1-Cyclopentylethanol (d) 1-Ethylcyclopentanol Answer: (a) (c) (b) (d) 11.47 Give stereochemical formulas for each product A-L and answer the questions given in parts (b) and (g). (a) 1-Methylcyclobutene (1) THF:BH3 (2) H2O2,OH - A(C5 H10 O) TsCl OH- B (C12 H16SO3) OHC(C5H10 O) (b) What is the stereoisomeric relationship between A and C? (c) B (C12H 16SO3 ) ID(C5 H9I) (d) trans-4-Methylcyclohexanol MsCl OH - E(C8H16 SO3) HC CNa F (C9H14) (e) (R)-2-Butanol NaH H(C4H9ONa) CH3 I J(C5H12O) (f) (R)-2-Butanol MsCl K(C5H12SO3) CH3ONa L(C5H12O) (g) What is the stereoisomeric relationship between J and L? A: CH3 H H CH3 CH3 H H CH3 H OH OH H H OTs OTs H A B CH3 OH OH CH3 CH3 I CH3 I H H H H H H H H C D H (b) A and C are diastereomers. H Ms Me O Me H H H E C2H5 C2H5 H3CO Me H Me H F C2H5 MsO Me H Me H C2H5 OCH3 Na O J K L (g) J and L are enantiomers. 11.48 When the 3-bromo-2-butanol with the stereochemical structure A is treated with concentrated HBr it yields meso-2,3-dibromobutane; a similar reaction of the 3-bromo-2-butanol B yields (+-)-2,3-dibromobutane. This classic experiment performed in 1939 by S. Winstein and H.J.Lucas was the starting point for a series of inverstingations of what are called neighboring rgroup effects. Propose mechanisms that will account for the stereochemistry of these reactions. Br H H3C OH CH3 H H H3C OH Br H CH3 a Register to View Answer b Br H Br H H3C OH H Br CH3 H H H3C OH2 H3C H H H3C Br Br CH3 H Br H CH3 H3C CH3 H Br Br CH3 Br H B: Br H H3C H H3C H CH3 H H3C H Br CH3 Br Br H CH3 Br H H3C OH H Br H CH3 H H3C OH2 Br Br H CH3 Br 11.49 Reaction of an alcohol with thionyl chloride in the present of a tertiary amine (e.g..pyridine) affords replacement of the OH group by Cl with the inversion of configuration (Section 11.14). However, if the amine is omitted, the result is usually replacement with retention of configuration. The same chlorosulfite intermediate is involved in both cases. Suggest a mechanism by this intermediate can give the chloro product without inversion. Answer: With amine: R3 R1 C R2 R2 R1C R3 O H O S RH2C O OH O R3 R1 Cl R2 O S C H O Cl O S Cl + Cl S - Cl Cl + HCl Cl Cl R3N + HCl O R3NH Cl O Cl + RH2C O S Cl RCH2Cl + O S Cl RCH2Cl + SO2 + Cl SN2 mechanim inversion of the configuration chlorosulfite Without amine: R3 R1 C R2 OH O R3 R1 Cl C R2 H O Cl O S R2 R1C O H O S Cl R2 R1C R3 O O S Cl + Cl S - Cl Cl R3 Cl R3 R1 C R2 Cl SN i mechanism retension of the configuration + SO2 11.50 Draw the stereoisomers that are possible for the compound 1,2,3-cyclopentanetriol. Label their stereocenters and say which are enantiomers and which are diastereomers. [Some of the isomers contain a pseudoasymmetric center, one that has two possible configurations, each affording a different stereoisomer, each of which is identical to its mirror image. Such stereoisomers can only be distinguished by the order of attachment of R versus S groups at the pseudoasymmetric center. Of these the R group is given higher priority than the S, and this permits assignment of configuration as r or s, lower case letters being used to designate the pseudoasymmetry.] Answer: OH OH OH OH OH OH OH OH OH OH OH OH A B C D The stereocanters are marked with *. B and C are enantiomers. AB, AC, AD, BD, CD are diastereomers.

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Duke - CHEM - 101
12.1 One method for assigning an oxidation state to a carbon atom of an organic compound is to base that assignment on the groups attached to the carbon; a bond to hydrogen for (anything less electronegative than carbon) make it 1, a bond to oxygen, nitro
Duke - CHEM - 101
13.1 (a) What product(s) would you expect to obtain if propene labeled with subject to allylic chlorination or bromination? (b) Explain your answer.H214C CHCH314C at C1 were+X2high temperature or low conc. of X2?(c) If more than one product would
Duke - CHEM - 101
14.1 Listed below are four compounds that have the molecular formula C6H6. Which of these compounds would yield only one monosubstitution product, if, for example, one hydrogen were replaced by bromine?(a) H3CCC C CCH3(b)(c)(d)Answer:(a) H3CC(a) a
Duke - CHEM - 101
16-1.(a)Give IUPAC substitutive names for the seven isomeric aldehydes and ketones with the formula C5H 8O (b).Give structures and names (common or IUPAC substitutive names)for all the aldehydes and ketones that contain a benzene ring and have the formula
Duke - CHEM - 101
17.1 For all practical purposes, the compound 2,4-cyclohexadien-1-one exists totally in its enol form. Write the structure of 2,4-cyclohxandien-1-one and of its enol form. What special factor account for the stability of the enol form? Answer:O OHBecaus
Duke - CHEM - 101
19.1 (a) Write a mechanism for all steps of the Claisen condensation that take place when ethyl propanoate reacts with ethoxide ion. (b) What products form when the reaction mixture is acidified? Answer: (a)O H3CHC H COC2H5 + OC2H5 H3CHC O COC2H5 + C2H5O
Duke - CHEM - 101
20.1 Outline a procedure for separating hexylamine from cyclohexane using dilute HCl, aqueous NaOH, and diethyl ether. Answer:organic phase: CH3(CH2)5NH2 dil HCl ether NaOH ether organic phase dry distill CH3 (CH2 )5NH2 dry distillaqueous phase20.2 Out
Duke - CHEM - 101
22.1 How many stereocenters are contained in the (a) aldotetrose and (b) ketopentose just given? (c) How many stereoisomers would you expect from each general structure?O CH CHOH CHOH CH2OHCH2OH C CHOH CHOH CH2OH OAn aldotetroseA ketopentoseThe answe
Duke - CHEM - 101
23.4 Give structural formulas for the products that you would expect from the following reactions:(a) -Pinene+ hot KMnO4(b) ZingibereneH+ H2PtH(c) CaryonphylleneCH 3+ HCl(d) -Selinene Answer:OH+ 2THF:BH3 (2)H2O2,OH(a)H(b)CH3ClHHCl(c
Duke - CHEM - 101
24.1 What form of glutamic acid would you expect to predominate in: (a) strongly acidic solution? (b) strongly basic solution? (c) at its isoelectric point (pI 3.2)? (d) The isoelectric point of glutamine (pI 5.7) is considerably higher than that of gluta
Duke - STAT - 101
Chapter 8 Hypothesis TestingSection 83z Test for a MeanChapter 8 Hypothesis TestingSection 83A report in USA TODAY stated that the average age of commercial jets in the United States is 14 years. An executive of a large airline company selects a samp
Duke - STAT - 101
Chapter 3 Data DescriptionSection 3-2 Measures of Central TendencyChapter 3 Data DescriptionSection 3-2 Exercise #361, 11, 1, 3, 2, 30, 18, 3, 7 The data above are the num er of b burglaries reported for a specific year for nine w stern Pennsylvania u
Duke - STAT - 101
Chapter 4 Probability and Counting RulesSection 4-2 Exercise #13 Sample Spaces and ProbabilityIf two dice are rolled one time, find the probability of getting these results. a. b. c. d. e. A sum of 6 Doubles A sum of 7 or 11 A sum greater than 9 A sum l
Duke - STAT - 101
Chapter 5 Discrete Probability DistributionsSection 5-2 Probability DistributionsChapter 5 Discrete Probability DistributionsSection 5-2 Exercise #19The probabilities that a patient wll have 0, 1, 2, or 3tests i 6531 perform d on entering a hospital a
Duke - STAT - 101
USING THE Z-TABLE Ex. 1) Find the area under the normal distribution curve. Between z=0 and z=0.75 Start by drawing the standard normal curve and shading the desired area. The shaded area looks like that in the chart. So, our answer will be the value we l
Duke - STAT - 101
Chapter 4: Probability & Counting RulesProbability: Probability is a likelihood or chance that a certain thing will happen. The thing that is happening is known as the outcome. Events are a set of possible outcomes. When tend to refer to the probability
Duke - STAT - 101
Chapter 5:Discrete Probability DistributionsWhat is a probability distribution? Probability Distribution gives all the possible outcomes and the probabilities associated with each. There are two (2) types of probability distributions. We have discrete a
Duke - STAT - 101
CHAPTER 6Ch 5 discusses discrete distributions. Ch 6 discusses a popular continuous distribution called the Normal distribution. Normal Distribution is a symmetric continuous distribution about the mean, . It is not the only symmetric continuous distribu
Duke - STAT - 101
WARNING: Due to the mere fact that we are covering chapter 10 before chapters 5-9, we will have to do a little creative editing. You will have to pay close attention to what is being covered in the notes and compare it to that in the text.Chapter 10INTR
Duke - STAT - 101
Chapter 1StatisticsWhat is it?the science of conducting studies to collect, organize, summarize, analyze, and draw conclusions from data (pg 4) statistics are used to describe or make inferences regarding a particular group or population.Why study it?
Duke - STAT - 101
Chapter 3: Data Descriptions In statistics, we like to describe what the data is telling us. It is important to distinguish between a statistic and a parameter. A statistic is obtained from a sample. A parameter is obtained from a population. We use bot
Duke - STAT - 101
USING THE Z-TABLE Ex. 1) Find the area under the normal distribution curve. Between z=0 and z=0.75 Start by drawing the standard normal curve and shading the desired area. The shaded area does not look like that in the chart. The chart will give from nega
Duke - STAT - 101
CHAPTER 7 INTRODUCTION TO CONFIDENCE INTERVALSWe now begin our study into inferential statistics. We are going to use statistics to infer what the data is telling us. In order to do so, we will use the normal approximation to the binomial, normal distrib
Duke - STAT - 101
HYPOTHESIS TESTING BACKGROUNDWhen most people think of inferential statistics, they think of hypothesis testing. Hypothesis tests are used to determine whether or not a drug is effective, whether a particular teachers students score better on the final t
Duke - STAT - 101
1 Population Hypothesis Test Flow ChartWhat are we testing?MeanIsProportionsDoes the normal approx. apply?known?VarianceYES, x z=NO Isn 30 ?n x zNO We will not discuss. NO x2 =(n 1) s 2 < < x + z 2 n 2 n t=2< 2 < (n 1) s 2(n 1) s 22 2
Duke - STAT - 101
Hypothesis Testing Steps1. 2. 3. 4. 5. Determine Ho and H1. Determine the test statistic / test value using the flow chart. * Determine the decision rule. Make a decision Write a conclusion. z Critical Value 0.10 Value 1.28 0.05 1.645 0.025 1.96 0.01 2.3
Duke - PHIL - 101
Theatre 101I.Worksheet 1general terms/conceptsArt: makes order out of chaos; man-made, therefore artificial. Fine Art: art made for entertainment, culture; brings us pleasure, sharpens our perception of life. All art requires knowledge, study and expe
Duke - PHIL - 101
Theatre 10172Worksheet 2Greek Theatrepage 57 -I.Concept: Man is the measure of all things, Fate Religious ritual: to honor the Gods, Dithryambs Epic Poetry-II.Theatre: educates, sets laws, and moral standardsSponsors: private enterprise along wit
Duke - PHIL - 101
Theatre 101Concept/Lifestyle:Worksheet 4Blood thirsty, competitive-Roman TheatreVariety entertainmentCompetitive arenaReligious ritual: to honor Gods, new Gods inventedTheatre: variety entertainment, comedy of characterSponsors: GovernmentAudience: f
Duke - CHEM - 201
Organic Chemistry I Exam 4 20101 Name KEYMultiple Choice - Circle the letter of the best choice for the answer to the question. (2 1/3 Points each) 1. The correct IUPAC name for the following compound is:BrA) 2-Bromo-4-methylenehexane C) E) 2-(2-Bromop
Duke - CHEM - 202
Organic Chemistry IDr Luke A. BurkeOrganic chemistry is the chemistry of Carbon and its compounds. For many scientists, the study of Organic Chemistry will be their only opportunity to explore synthesis. All sciences use analysis where ideas or things a
Duke - CHEM - 202
Structure and Properties of Organic Molecules Electrons exhibit wave-particle duality. 1) The particle property gives a meaning of here at this spot at this time and going off in a particular direction with a certain speed (billiard ball). Localized desri
Duke - CHEM - 202
Alkanes Alkanes are the simplest organic molecules, they only contain C and hydrogen, and only contain single bonds. Compounds that have the maximum number of bonded hydrogens, are said to be saturated. Alkanes are saturated hydrocarbons. General Formula:
Duke - CHEM - 202
The Study of Chemical Reactions Mechanism: The complete, step by step description of exactly which bonds are broken, formed, and in which order. Thermodynamics: The study of the energy changes that accompany chemical and physical transformations. It allow
Duke - CHEM - 202
Stereochemistry This is study of the 3 dimensional arrangement in space of molecules. In organic chemistry, subtle differences in spatial arrangements can give rise to prominent effects. E.g. the isomers of butenoic acid:H HO2C CO2H H HO2C CO2Htrans iso
Duke - CHEM - 202
Alkyl Halides Alkyl halides are a class of compounds where a halogen atom or atoms are bound to an sp3 orbital of an alkyl group. CHCl3 (Chloroform: organic solvent) CF2Cl2 (Freon-12: refrigerant CFC) CF3CHClBr (Halothane: anesthetic) Halogen atoms are mo
Duke - CHEM - 202
Structure and Synthesis of Alkenes Alkenes (olefins) are hydrocarbons which have carboncarbon double bonds.H H CC H HA double bond is a bond and a bond. Double bond B.D.E. bond B.D.E. = 146 kcal/mol = 83 kcal/molTherefore B.D.E. must = 63 kcal/mol. A b
Duke - CHEM - 202
Reactions of Alkenes Since bonds are stronger than bonds, double bonds tend to react to convert the double bond into bonds+ X-Y XYThis is an addition reaction. (Other types of reaction have been substitution and elimination).Addition reactions are typi
Duke - CHEM - 202
Alkynes Alkynes or acetylenes are compounds that contain a carboncarbon triple bond. E.g.HCCH acetylene CH3CH2 C C H H3C C C CH3The triple bond results in a molecular formula of CnH2n-2 Ethane Ethene Ethyne C2H6 C2H4 C2H2 0 elements of unsaturation 1 el
Duke - CHEM - 202
Synthesis and Structure of Alcohols Alcohols can be considered organic analogues of water.HOH ROHAlcohols are usually classified as primary, secondary and tertiary.H R H primary OH R R secondary H OH R R tertiary phenol R OH OHAlcohols with the hydrox
Duke - CHEM - 202
Reactions of Alcohols Alcohols are versatile organic compounds since they undergo a wide variety of transformations the majority of which are either oxidation or reduction type reactions. Oxidation is a loss of electrons Reduction is a gain of electrons.
Duke - CHEM - 202
Infrared Spectroscopy and Mass Spectrometry Introduction It is fundamental for an organic chemist to be able to identify, or characterize, the new compound that he/she has just made. Sometimes this can be achieved by a chemical means, such as determining
Duke - CHEM - 202
Nuclear Magnetic Resonance (NMR) Spectroscopy NMR is the most powerful analytical tool currently available to an organic chemist. NMR allows characterization of a very small amount of sample (10mg), and does not destroy the sample (non-destructive techniq
Duke - CHEM - 202
Organic Chemistry II with Prof. BurkeLecture Notes Email Room Office Hours Texthttp:/camchem.rutgers.edu/~burke burke@camden.rutgers.edu Sci 114B Half-hour before and after each lecture or by appt. (a) Organic Chemistry Wade, 4th ,5th, or 6th Edition (b
Duke - CHEM - 202
Conjugated Systems, Orbital Symmetry and UV Spectroscopy Introduction There are several possible arrangements for a molecule which contains two double bonds (diene): Isolated: (two or more single bonds between them)Conjugated: (one single bond between th
Duke - CHEM - 202
Aromatic Compounds Historically, benzene and its first derivatives had pleasant aromas, and were called aromatic compounds. Structure of Benzene Kekul Structure Kekul (1866) bravely proposed that benzene had a cyclic structure with three alternating C=C d
Duke - CHEM - 202
Reactions of Aromatic Compounds Just like an alkene, benzene has clouds of electrons above and below its sigma bond framework.Although the electrons are in a stable aromatic system, they are still available for reaction with strong electrophiles. This ge
Duke - CHEM - 202
Ketones and Aldehydes The carbonyl group is of central importance in organic chemistry because of its ubiquity. Without studying the carbonyl group in depth we have already encountered numerous examples of this functional group (ketones, aldehydes, carbox
Duke - CHEM - 202
Amines Amines are derivatives of ammonia with one or more alkyl groups bonded to the nitrogen. Amines can be classified as primary, secondary or tertiary, meaning one, two and three alkyl groups bonded to the nitrogen respectively. E.g.Prim ary Am ines N
Duke - CHEM - 202
Carboxylic AcidsWhen a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids.O R C O-HRCO2HRCOOHCarboxylic acids are classified according to the substituent that is bonded to the car
Duke - CHEM - 202
Carboxylic Acid DerivativesCarboxylic derivatives are described as compounds that can be converted to carboxylic acids via simple acidic or basic hydrolysis. The most important acid derivatives are esters, amides and nitriles, although acid halides and a
Duke - CHEM - 202
Duke - CHEM - 202
Duke - CHEM - 202
Duke - CHEM - 202
Duke - CHEM - 202
Duke - CHEM - 201
Chapter 24 Organic ChemistryStudent: _ 1. The general formula for alkenes is A. CnH2n+2 B. C2nH2n C. CnHn+2 D. CnH2n E. CnH2n-2 2. The general formula of an alkane is A. CnH2n B. CnH2n+2 C. CnH2n-2 D. CnH2n+4 E. CnH2n-4 3. Which one of these formulas is
Norfolk - CHM - CHM-331
CalculatorPotentiometric Titration of Hydrogen PeroxideOne method of determining the concentration of a hydrogen peroxide, H2O2, solution is by titration with a solution of potassium permanganate, KMnO4, of known concentration. The reaction is oxidation
Norfolk - CHM - CHM-331
17-3 Sodium Hydroxide and Carbon Dioxide: Why it is Important to Keep Your Standard NaOH Solutions CappedDescription: A sodium hydroxide solution is added to a PET soda bottle that is filled with CO2. The bottle is quickly capped and shaken. The bottle c
Norfolk - CHM - CHM-331
Chapter 17Acid-Base Equilibria81John A. Schreifels Chemistry 212Chapter 17-1Overview Solutions of a Weak Acid or Base Acid ionization equilibria Polyprotic acids Base ionization equilbria Acid-Base properties of Salts Solutions of a Weak Acid or B
UCSB - HISTORY 10 - 101
L ucas Whelan 2/2/10 H istory 101 Yugoslavia chapter summary The question of a unified Slavic state was one that brought great d ifficulties to the Peace Conference in 1919. South Slav unity would especially be a difficult task given that several soldiers