CHEM 242 ORGANOMETALLIC COMPOUNDS CHAP 15 ASSIGN. , would be? CH 3 CHOCH 2 CH 2 OH CH 3 CHCH 2 CH 2 OH A B C D E

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1 HEM 242 RGNMETLLI MPUNDS HP 15 SSIGN 1. The final product, D, in the following reaction sequence, H 2 H 2 HH P 3 Mg ether B H 3 D, would be? HH 2 H 2 H HH 2 H 2 HH 2 H 2 H HH 2 HH 2 B D E 2. What is the product,, that would be obtained from the following reaction sequence? H 2 Mg H H H 3 H H 2 H HH 2 H 2 H HH I II III H HH HH 2. I. III D. E. 3. What would be the product,, of the following reaction sequence? H 2 Li ether ui B HH 2 H 2. 2,6-Dimethylheptane B. 2,2-Dimethylpropane. 2-Methylpentane D. 2,2,5-Trimethylhexane E. 2,2,6-Trimethylheptane 1 P a g e

2 4. What would be the product,, of the following reaction sequence? H 2 H Mg N ether D 2 H 2 H. H 2H 2 B. D. D. H 2H 2H 2D E. H 2H 2H 2D H 2 H D 5. What is the product,, that would be obtained from the following reaction sequence?. I. III D. E. H H P 3 Li ( ) 2 = NH 4 l H 10 o I II III H 6. What would be the final product,, in the following reaction sequence?. I. III D. E. H P 3 Mg, Et 2 H 3 H heat H I II III H 7. What would be the major product of the following reaction?. (R)-3-ethyl-5-methylheptane B. (R,S)-3-ethyl-5-methylheptane. (S)-3-ethyl-5-methylheptane D. (3R,5S)-5-ethyl-3-methylheptane E. (3S,5R)-5-ethyl-3-methylheptane l Li, Et 2 ui H 2 P a g e

3 8. What is the principal product(s) formed when 1 mol of methylmagnesium iodide reacts with 1 mol of p-hydroxyacetophenone?. I. III D. E. IMg H MgI MgI H 4 H I II III MgI IMg 9. The reaction of lithium diethylcuprate with 1-bromo-4,4-dimethylhexane yields:. 3,3-Dimethylheptane B. 3,3-Dimethyloctane. 1-Ethyl-4,4-dimethylhexane D. Di-4,4-dimethylhexylcuprate E. None of the above 10. Which of the following synthetic procedures would be employed most effectively to transform ethanol into ethyl propyl ether?. Ethanol H, then Mg/ether, then H 3, then NaH, then H 2 B. Ethanol H, then Mg/ether, then HH, then H 3, then NaH, then H 2. Ethanol H 2H 2H H 2S 4/140 D. Ethanol NaH, then HH, then H 3, then H, then Mg/ether, then H 2H 2 E. Ethanol H 2S 4/180, then H 2H What is the principal product of the following reaction: H H 2 HH 2 H 2 H 2 H 2H 2H 2Mg/ether; then H 2? H ) H 2 H B. HH 2 H 2 H 2 H 2 H HH 2 H 2 H 2. HH 2 H 2 H 2 H 2 D. H 2 H HH 2 H 2 H 2 H 2 E. H 2 H 2 H 2 3 P a g e

4 6 H 5 H 2 H Your task is to synthesize H through a Grignard synthesis. Which pairs of compounds listed below would you choose as starting materials? H H. 3 H 2 H 2 and 3 6 H 5 B. H 2 H 2 H and 6 H 5 H 2 H and. 6 H 5 H D. More than one of these. Which ones? E. None of these 13. Your task is to synthesize 2-phenyl-2-hexanol through a Grignard synthesis. Which pair(s) of compounds listed below would you choose as starting materials? H H. 3 H 2 H 2 and 3 6 H 5 B. H. 3 H 2 H 2 H 2 and 6 H 5 D. nswers or B E. nswers or 14. Which combination of reagents is to be preferred for the synthesis of 2,4-dimethylhexane by the orey-posner, Whitesides-House procedure?. Lithium diisobutylcuprate sec-butyl bromide B. Lithium dimethylcuprate 2-bromo-4-methylhexane. Lithium dimethylcuprate 4-bromo-2-methylhexane D. Lithium diisopropylcuprate 1-bromo-2-methylbutane E. Lithium di(2-methylbutyl)cuprate isopropyl bromide 15. Which Grignard synthesis will produce an optically active product or product mixture?. Mg B. HH 2 and lmg 6 H 5. MgI D. H MgI E. H 3 H Mg 4 P a g e

5 16. Which of the following would serve as a synthesis of racemic 2-methyl-1-phenyl-2-butanol?. I. III D. ll of the above E. None of the above H 2 H? I H 2 1. Et 2 H 2 Mgl 2. NH 4 II H 2 H 2 Mg 1. Et 2 2. NH 4 III H 2 H 2 MgI 1. Et 2 2. NH Which of the following is the strongest acid?. RMgX B. Mg(H)X. RH D. H Which of the following is the strongest base?. RMgX B. Mg(H)X. RH D. H Grignard reagents react with oxirane (ethylene oxide) to form 1 alcohols but can be prepared in tetrahydrofuran solvent. Why is this difference in behavior observed?. Steric hindrance in the case of tetrahydrofuran precludes reaction with the Grignard. B. There is a better leaving group in the oxirane molecule.. The oxirane ring is the more highly strained. D. It is easier to obtain tetrahydrofuran in anhydrous condition. E. xirane is a cyclic ether, while tetrahydrofuran is a hydrocarbon. 20. Which of these compounds cannot be used to prepare the corresponding Grignard reagent?. H 2H 2H 2 B. () 3l. H 2=HH 2 D. () 2NH 2H 2 H E. H 2 H 2 I F. H=HH 2H Which of these is most likely to be a successful synthesis of an organometallic compound?. H 2H 2Mg Lil H 2H 2Li Mgl B. 2 H 2H 2H 2Li Znl 2 (H 2H 2H 2) 2Zn 2 Lil. 3 (H 2) 2Hg 2 ll 3 2 (H 2) 3l 3 Hgl 2 D. (H 2) 3l 3 Nal 3 H 2Na ll 3 E. () 2u Mg 2 () 2Mg u 2 5 P a g e

6 22. If the role of the solvent is to assist in the preparation and stabilization of the Grignard reagent by coordination with the magnesium, which of these solvents should be least effective?. I. III D. E. H 2 H 2 ( H 2 ) 3 N I II III (H 2 ) 4 H 2 H What is the product of the following reaction? 1) H H 3) H H 1) 2 Mg 2) H 3 2) H 4) H Phenylnaphthalene, shown below, can be prepared in over 80% yield by one of the reactions below. Which one? 6 H 6, ll 3 1) 3) l 6 H 5 Mg diethyl ether 6 H 5 I ( 6 H 5 ) 2 uli 2) 4) diethyl ether 6 H 5, ll How many stereoisomers are formed in this reaction?. just one B. two. three D. four 26. Reaction of excess Grignard reagent with diethyl carbonate, shown below, gives a(n): Et Et. ketone B. tertiary alcohol. secondary alcohol D. ester 6 P a g e

7 27. What is being made in this reaction? 28. Which of the following are intermediates in the reaction of excess methylmagnesium bromide with ethyl benzoate (shown below) to make 2-phenyl-2-propanol? 6 H 5 Mg H 2 6 H 5 Mg 6 H 5 B 6 H 5 Et Mg (xs) diethyl ether H 3. and B B. and. B and D., B, and 29. onsider the two syntheses of the compound below. Which method would work best with minimal byproducts? Method I NBS, l 4 (heat) benzoyl peroxide NaH H 2 H. Method I. B. Method II.. Both methods would work. D. Neither method will work. Method II 2, Fe 3 Mg, diethyl ether (1) H 2 = (2) H 3 EXTR REDIT 30. What is the product of the following sequence of reactions?. 1,1-diethylcyclopropane B. trans-1,2-diethylcyclopropane. cis-1,2-diethylcyclopropane D. cis and trans-1,1-diiodo-2,3-diethylcyclopropane H 2 H (1) NaNH 2, NH 3 H 2 H 2 I 2 (2) H 2 Lindlar Pd Zn(u) 7 P a g e

8 NME DTE NSWER SHEET HEM 242 HP 15 SSIGN SPRING P a g e