Summ09Ex2

Summ09Ex2 - l . "Grade or Education" = 1...

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Unformatted text preview: l . "Grade or Education" = 1 CHEM 2261/01 Summer 09 Exam 2 Chapters 4-6 Draw out the mechanism for the reaction shown below. Use this mechanism along with the numbered figures below to find the number representing a process which does NOT occur in the reaction mechanism. CH3 Br CH3 CH3 CH3 CH2 CH B + HBr _> 3 + CH3 +(I3H3 CH3 CH3 CH3 CH3 CH2 )CHCH3 + CH3 CH3 fl: Er: CB. __ '- +\_: Br? 1 2 3 4 " 5 Process 3 does not occur in this mechanism. Process 5 does not occur in this mechanism. A B C. Process 1 does not occur in this mechanism. D Process 4 does not occur in this mechanism. E Process 2 does not occur in this mechanism. Rationale: Chapter 4 Problem 62a Figure out what will be the major product of the reaction of 2—methyl—2—butene with each of the reagents given in the multiple choices. Pick the choice which CORRECTLY matches the product structure with one of the structures shown below. 9H3 9H3 9H3 CH-SCH-CIDH-CH3 cH3 CH-SC-CH-ZCHS CH3 c2H-3c—c|:H-CH3 CH3 Br CH-3c|:—cl:H-CH3 Br CH-3CID—(I3H-CH3 Br OH c3H-3C—CH-CH3 1 Cl Br 3 Br CI 5 Ho Br 2 4 6 B rZ/CHZCIZ will react to give 2 as the major product. BrZ/CH30H will react to give 5 as the major product. A B C. HBr will react to give 1 as the major product. D BrZ/NaCl will react to give 4 as the major product. E B rZ/HZO will react to give 6 as the major product. Rationale: Chapter 4 Problem 40(a,g,j,k,l) Mevacor, shown below, is used clinically to lower serum cholesterol levels. How many asymmetric centers does Mevacor have? Mevacor __ A. __ B. __ C. __ D. 10 __ E. 7 Rationale: Chapter 5 Problem 66 Find the structures of the products of the reactions given in the multiple choices among the Fisher projections numbered 1, 2, and 3 below. Pick the choice which indicates the CORRECT product(s) of the reaction given. CHZCH3 CHZCH3 CHZCHS H Br H Br Br H H Br Br H H Br CHZCH3 CHZCH3 CHch3 1 2 3 trans—3—hexene + Brz/CH2CIZ —> product 3 cis—3—hexene + Brz/CH2CIZ —> product 1 and 3 A B __ C. trans—3—hexene + Brz/CH2CIZ —> product 1 D cis—3—hexene + Brz/CH2CIZ —> product 1 E __ . trans—3—hexene + Brz/CH2CIZ —> products 2 and 3 Rationale: Chapter 5 Problem 82(e,f) Which of the numbered structures shown below is (2R,3R)—2,3—dichloropentane? CH3 CH3 CH3 CH3 CI H H Cl CI H H Cl CI H H CI H CI CI H CHZCH3 CHZCHS CHZCHS CHZCH3 1 2 3 4 __ A. None of these structures is correct. __ B. 1 __ C. 4 __ D. 2 __ E. 3 Rationale: Chapter 5 Problem 88b 6- Which of the structures below is/are (S)—2—chlorobutane? CI CI / H /\/ (3H3(;H2 C 3 H E H CH3 H a c e CH3 CH3 H+CI 9' H H /'\/ CHZCH3 H CI CH3 b d f Only b is (S)—2—chlorobutane. Structures b and c are (S)—2—chlorobutane. A B C. Structures a, c, and d are (S)—2—chlorobutane. D Structures b, d and f are (S)—2—chlorobutane. E Only c is (S)—2—chlorobutane. Rationale: Chapter 5 Problem 78 7. Which of the cations whose structures are shown below WOULD be expected to rearrange? + CH2 C53 CH3 9H3 9H3 + CH-SCH-EIEH-CH3 CH-SSIE-CH-ZCH3 CH-3CH-2S3-H-CH3 a b c d e f Only the cation labelled b would be expected to rearrange. Only the cation labelled d would be expected to rearrange. A B C. The cations labelled a, b, and e would be expected to rearrange. D The cations labelled c, d, and f would be expected to rearrange. E All of these cations would be expected to rearrange. Rationale: Chapter 4 Problem 15 8- Figure out what reagents could be used to carry out the syntheses shown below. Pick the choice which specifies the CORRECT reagent(s) for one of these syntheses. RCHZCH3 o /\ RCH=CH2 RCH_CH2 \ B | r RCECH R-C—CH «— R-CH—CH I 3 I 3 Br Br E/ RC=CH 0 gr 2 R-IdCH3 ll RCH5CH The reagent used to carry out the synthesis associated with box 7 is Bra in CH ZCIZ. A __ B. The reagent used to carry out the synthesis associated with box 1 is excess Hz with Pd/C. C The reagent used to carry out the synthesis associated with box 8 is excess Hz with Pd/C. D —— - The reagents used to carry out the synthesis associated with box 5 are BH3 followed by HO', H202, and H20. __ E. The reagents used to carry out the synthesis associated with box 3 are excess Hg with Pd/C followed by HBr. Rationale: Chapter 6 Problem 29 The compound whose structure is shown in the center of the figure following can be converted into all of the other outer compounds whose structures are shown. Conversion number 1 transforms the center compound into the topmost compound in the figure (see boxed number 1). Conversion number 2 transforms the center compound into the outer compound one position clockwise from the topmost compound, etc. (ie. the conversion numbers are arranged in a clockwise pattern). Use this information to find the multiple choice answer which is CORRECT. C H—C H—2 Br Br 0ch HECH-ZOH CHEC HECHS 1 CHECIDO:—CH3 CHZ—CHZCHZ CH§$H_CH3 lE/l/ Br CHECH—CH3 CHECH—CHZ (IDCH3 \o/ CHECH—CH—ZBr | OH Conversion number 3 can be carried out using BrZ/CHZCIZ. Conversion number 1 can be carried out using Brz and H20. A B __ C. Conversion number 5 can be carried out using Brz and CH30H. D Conversion number 2 can be carried out using HZSO4/HZO. E —— - Conversion number 8 can be carried out using BH3 followed by H202 and base (HO_). Rationale: similar to Chapter 4 Problem 47 10. 11. Pick the choice which gives a CORRECT systematic name for one of the compounds whose structures are shown below. CH3 I (IDHZCH2 CHE—.CH-CH-ZCE C-CH-ZCH3 CHBCHQCH: C.CH.ZCH.ZCECH a 9 g CH3 CH3 HO-CH'ZCH-ZCECH CH-SCHZC-CH-ZCH-CHEOH Q f Compound d is l—butyn—4—ol. Compound f is 2,4—dimethyl—4—hexen—1—o|. A B C. Compound c is 3—(3—butynyl)—1 ,3—hexadiene. D Compound b is 3—methyl—2,5—hexadiene. E Compound a is 3—heptyn—6—ene. Rationale: Chapter 6 Problem 6(a,b,c,d,f) Pick the choice which CORRECTLY describes how cis—Z—octene could be synthesized starting with acetylene. —— A- First react the acetylene with _NH2. Next react with CH3CH2CH2CH2CH2CHZBr. Finally react with HZ/Lindlar catalyst to form cis—Z—octene. —— B- First react the acetylene with _NH2. Next react with CH3CH2CH2CH2CH2CHZBr. Finally react with H2 and Pt/C to form cis—Z—octene. —— C- First react the acetylene with _NH2. Next react with CH3CH2CH2CH2CH2CHZBr. Finally react with Na/NH3(|) catalyst to form cis—Z—octene. —— D- First react the acetylene with _NH2. Next react with CHgBr. Next react with more _NH2. Next react with CH3CH2CH2CHZCHZBr. Finally react with HZ/Lindlar catalyst to form cis—Z—octene. —— E- First react the acetylene with _NH2. Next react with CHgBr. Next react with more _NH2. Next react with CH3CH2CH2CHZCHZBr. Finally react with Na/NH3(|) to form cis—Z—octene. Rationale: Chapter 6 Problem 51a 12. Figure out whether each of the following pairs of compounds are identical, or are enantiomers, diastereomers, or constitutional isomers. Pairs of compounds share the same letter, like a1 and a2. Choose the CORRECT statement from the multiple choices. CH3 CH3 H<|3=CH2 CIDH-ZCH3 CHZOH CHZCHS Ho H H OH Cm Cm H+CH CH+H CHCH/ \CHS H/ \ CH3 3 3 H CI CI H 3 2 H Hc=CH2 CHZCH3 CHZOH CH3 CH3 ‘31 a2 b1 b2 c1 c2 CH3 CHZCH3 Ho H Ho H H CI H CI CHZCH3 CH3 d1 d2 f1 f2 a1 and a2 are identical. c1 and c2 are diasteriomers. A B C. b1 and b2 are enantiomers. D f 1 and f2 are enantiomers. E d1 and d2 are diasteriomers. Rationale: similar to Chapter 5 Problem 76 (a,b,c,d,f) 13. Pick the choice which CORRECTLY describes how 4—bromo— 3—hexanol could be synthesized starting with acetylene. First react the acetylene with _NH2. Next react with CH3CHZBr. Next react with more _NH2. Next react with more CH3CHZBr. Next react with BrZ/CHZCIZ. Finally react with HZ/Pd/C to form 4—bromo— 3—hexanol. First react the acetylene with _NH2. Next react with CH3CHZBr. Next react with more _NH2. Next react with more CH3CHZBr. Next react with H2 and Pd/C. Finally react with BrZ/CHZCIZ to form 4-bromo— 3—hexanol. First react the acetylene with _NH2. Next react with CH3CHZBr. Next react with more _NH2. Next react with more CH3CHzBr. Next react with BrZ/HZO. Finally react with Na/NH3(|) catalyst to form 4—bromo— 3—hexanol. First react the acetylene with _NH2. Next react with CH3CHZBr. Next react with more _NH2. Next react with more CH3CHzBr. Next react with BrZ/HZO. Finally react with HZ/Lindlar catalyst to form 4—bromo— 3—hexanol. First react the acetylene with _NH2. Next react with CH3CHZBr. Next react with more _NH2. Next react with more CH3CHzBr. Next react with HZ/Lindlar catalyst. Finally react with BrZ/HZO to form 4—bromo— 3—hexanol. Rationale: Chapter 6 Problem 51c 14. Figure out what reagents are required to convert the alkene labelled A shown below into the alcohols labelled B, c, and D. Choose the CORRECT statement from the multiple choices. >40: B M —> A C OH MOH D —— A- Alkene A will react with: 1. BH3/THF; followed by 2. H202, HO_, H20 to form alcohol c. __ B. Alkene A will react with: 1. Hg(OAc)2, HZO/THF; followed by 2. NaBH4 to form alcohol D. __ C. Alkene A will react with H20 and H2804 to form alcohol c. __ D. Alkene A will react with H20 and H2504 to form alcohol D. __ E. Alkene A will react with H20 and H2504 to form alcohol B. Rationale: Chapter 4 Problem 43 15. Examine the Fischer projections below. Which of the multiple choices gives the number(s) associated with the Fischer projection(s) of the CORRECT stereoisomer(s) obtained from the reaction of 2—butyne with the reagents specified? CH3 CH3 CH3 CH3 CH3 CH3 Br H H Br H Br Cl Br Br CI Cl Br H: Br BriH H:’: Br Brj: CI Cl: Br Cli Br CH3 CH3 CH3 CH3 CH3 CH3 1 2 § 5 § § __ A. Reaction with, 1. Na/NH3(liq), followed by 2. Bra/CHZCIZ gives the products with structures 4 and 5 only. __ B. Reaction with, 1. HZ/Lindlar catalyst, followed by 2. Bra/CHZCIZ gives the products with structure 3 only. __ C. Reaction with, 1. Na/NH3(liq), followed by 2. BrZ/CHZCIZ gives the products with structures 1 and 2 only. __ D. Reaction with, 1. Clz/CHZCIZ, followed by 2. Bra/CHZCIZ gives the products with structure 6 only. __ E. Reaction with, 1. Na/NH3(liq), followed by 2. Bra/CHZCIZ gives the product with structure 6 only. Rationale: Chapter 6 Problem 44 1O 10. 11. 12. 13. 14. 15. Answer Key "Grade or Education" CHEM 2261/01 Summer 09 Exam 2 Chapters 4-6 1 11 ...
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Summ09Ex2 - l . &amp;quot;Grade or Education&amp;quot; = 1...

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