Chem109B Midterm 1 Key W'12 - 1(3 minutes 10 points Give...

This preview shows page 1 - 9 out of 9 pages.

Image of page 1
Image of page 2
Image of page 3
Image of page 4
Image of page 5
Image of page 6
Image of page 7
Image of page 8
Image of page 9

You've reached the end of your free preview.

Want to read all 9 pages?

Unformatted text preview: 1. (3 minutes, 10 points! Give the major product ofeach ofthe following reactions, or ifno reaction will occur, so state. 0 O u a. g LAICIz gc‘ow‘s + / \ CH3CHa Cl 2.H20 b. O. + HB+ —-> give the majorphenolic product 9‘3 CH ~a c. I 3 AlCl; Cr £793 + CH3CIECH2Cl —-> (45 CH3 Cl d. U + (CHgCHobCuLI E» / r O \ e. PdL \O HO \S‘T’M 9 (9 WWWLLQ, wiaw‘s tutu/o \ l : 1. [m A; < 61/ «a» W 0H 7. 6minutes 12 oints 4—’—‘9—’ wig Answer the following: a. For the following reaction. what monohalogenated product would be obtained in greatest yield? CH7, CH7, CH3 9’3 Co, b. For the following reaction, what monohalogenated product would be obtained in greatest yield? h as as V CH3CHCH2CH2CHCH3 + Br2 ——> 0136!, any W4 0‘5 (In. c. Which of the following is the least reactive toward electrophilic aromatic substitution? 0 : ,NHCH3 : CH3 : ,OCH3 ©CH20CH3 : ,ogCH3 d. Draw the structure of butyllithium. 05%»; 0:2 Eu e. Which ofthe following alkyl halides could not be used for a Suzuki reaction? WBF Wm ® f. Which ofthe following compounds could not be synthesized from bromobenzene in a Heck reaction? Q/V UV Give the mechanism for the following reaction. (Make believe the person grading this question has noU idea of how the reaction happens but will understand it easily by following your mechanism.) st04 NO? + __‘> m fl r? “"0505’4 '—’> ‘4?”Moz ———» Hg) +— woo; +- + L307, U07. / 8. (6 minutes, 6 points) Give the mechanism for the following reaction. labeling initiation, propagation. and termination steps (show all 3 termination steps). You do not need to show curved arrows. peroxide RCH=CH2 + HBr —> RCHz—CHzBr @oofl— —-———-» go. .02, 20- +—(+f57~ __/A> @014. +— Way— (’5)! i- rLCA4=c¢iZ———» (L944—C4gt’zrr mac/Uda- + l—H’m‘ «a Kuwaiti/1x» + (’vr‘ flaw—kw A667”; (Awakpfir + ‘(Lpr' .——> Eloaoubf’zrr fir. raglame 4' (lg/Huiflr —/—b flfACULPm" £0“qu 3. (8 minutes, 14 points! Answer the following: a. Which is more reactive, an organolithium compound or aompound? (electronegativities: C = 2.5, Li = 1.0. Na = 0.9) b. Write the reaction, showing the reactant(s) and product(s), that is known as oxidative addition—the first step in both the Suzuki and Heck reactions. L L.. \ / (4,, 4. my, fl.» a K/ \@r c. What alkyl halide would you need as a reactant for the synthesis of l—hexanol, formed by converting the alkyl halide to a Grignard reagent, which then reacts with and ethylene oxide followed by the addition of water? alga ll’C/LLLCLLSZ W (1. Which ofthe following would be the most reactive toward electrophilic aromatic substitution (EH3 l ~ ~ I C 2CH2N+CH3 CHZNPH} I\II§H3 c. Give an example ofa substituent on a benzene ring that withdraws electrons inductively and donates electrons by resonance CH; I l O 0 [L H- /‘0H /02' /’UHL flc'fl /pll’o‘¢' /PO'r CCQ) I: P) f. Would butylmagnesium chloride be more apt to undergo a transmetallation reaction with lithium chloride or with . (electronegativities: C = 2.5, Mg = 1.2, Li = 1.0. Cu = 1.8) g. In which orbital are the lone pair electrons on the nitrogen atom of pyridine? s p .3173 .s'p 6. 18 minutes, 20 points! Answer the following: a. What role does AlCl3 play in the Friedel-Crafts acylation of benzene by an acyl chloride? It binds to the carbonyl oxygen to make the acyl chloride more electrophilic. lt chlorinates the acyl chloride. It r cts with benzene to form an electrophilic species. It removes the chlorine from the acyl chloride to form an acylium ion It acts as a nucleophile toward benzene. b. Which ofthe following is the least basic? CH3 I ‘ r—\— / CH3CH2NCH2CH3 N NH NH3 V \N c. Which alkene forms the same product when it reacts with HBr in the presence of peroxide as it forms when it reacts with HBr in the absence ofperoxide? l-hexene 2-methyl-2-butene l-methylcyclohexene 3-methyl-3-hexene (:1. Which ofthe following alkylbenzenes could not be oxidized to benzoic acid using KMnO4/A/acid? ethylbenzene 3,3-dimethyl-l -phenylbutane toluene isopropylbenzene e. Which ofthe following statements is true? The most selective reagents are the most reactive reagents. The greater the reactivity ofa radical, the more selective it will be. The lower the reactivity ofa radical. the less selective it will be. Reactivity and selectivity are completely independent. he greater the reactivity ofa radical, the less selective it will u . f. Which of the following is NOT true about electrophilic aromatic substitution reactions? The rate-limiting step is always addition of the electrophile to the aromatic ring. The product of an electrophilic aromatic substitution is not aroma I . Other than the generation of the electrophile, all electrophilic aromatic substitution reactions have the same mechanism. The proton removed from the ring comes from the carbon where the electrophile was added. The carbocation intermediate is resonance stabilized. g. Which of the following features is NOT characteristic of aromatic compounds? They are planar. The contain an odd number of pairs of pi electrons. They have an uninterrupted cloud of delocalized pi electrons. < The ring atoms must be carbon atoms. > hey are cyclic. b. What is the major product of the Friedel-Crafts alkylation of benzene when l-chlorobutane is used as the alkyl halide? The major product is 2-methyl-1-phenylpropane. The major product is 2-methyl-2—phenylpropane. The major product is 3—phenylbutane. The major product is l-phenylbutane. he major product is 2-phenylbutane. ) i. Which of the following compounds has the lowest pKa value? cyclopropene cycloheptatriene 1,4-pentadiene benzene j. Which ofthe following compounds is the least stable? 1,3-butadiene cyclooctatretraene benzene naphthalene cyclobutadiene 10. (3 minutes, 8 points! 2. Draw a circle around the aromatic compounds. ©@ 0 .0 b. Draw a circle around the antiaromatic compounds. @0 so 11. (5 minutes, 10 points! Name each of the following: CH3 OH [email protected] .E 4. (3 minutes, 10 points) Give the major product of each ofthe following reactions. or ifno reaction will occur, so state. 7 OHL Clle 3. ac“- :fi far 4* g Dub b- N02 Pd/C \ + H7 l / O on I c / LCH CH MgBr 4—6440 CH3CH—3CHCH3 —3h°- “5&5? '5 2.HCl we d \ Br + \A -——> \ (CH3CH2)3N / Grubbs e Gd catalyst : l +- Gui-$00.; \ \SWM (fr _ 0% amw’ \ 33W ...
View Full Document

  • Winter '10
  • lipshutz

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern