PracticeExamIII_2007

PracticeExamIII_2007 - oRGANtc CHEMISTRY LAB any NAME K6 Y...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: oRGANtc CHEMISTRY LAB any NAME K6 Y EXAM a, zoo? TA Please write claarlg,T and answer the questions directly and concisely. Partial credit will be given where appropriate. The total number of points in this exam is St}. Total scores will be multiplied by 2 to obtain the final soorc out of 163 pts. 1- {it} tits.) Indicate how you would synthesize compound A, shown below, starting from an afi— unsaturatcd carbonyl compound. More lhan one reaction is required. For each reaction, give the starting material, the reagents and conditions, and the product. '. Compoundfit: D D Q E) O LNmom D ID \JK/ /” ‘K 3’ "1“ ohm \/ Omit *“9 0% \ {+11%} A. K 9.: Nam-i} H 0 £5 C) C) ”ant-iii that: o f 0 AV/ / D J “N E} 1V + L 1 /G h 2. {a} [5 pts.) Write a mechanism for the reaetitm shewn below. HEP};1 C]; i—jk LP? Bar E39 0 G) O «not-11 “5-) (4' 3%?) “xx-J @( W 4» o {b} (3 pte.) In the reaction ebDVe, Whyr is aeetie anhydride used as the solvent? in when we the 5&9}me weer! Mk W ’flu CatrioqcyBYxis-ry 0 03k {1: 9351‘s“ ta \lfim U U S rm WQRJ JKVJK Jr MD ~—§Z}kw {e} (1?. pte.) The trity] eetien shown above is Very stable. How eeuld the trity] cation structure be medified te make it even were stable? ‘K’N mam Fmodfi mm W WEI“ m3} Elm (JDQLM New?“ {Take 3Q 'Hxi. wetokwn <1 2 e-‘< FE them. “A“ e flit-Emma. firm?" . ”an . }\ 3. {ID pigs.) The carhunyl shflch-fmquencieg obtained from the IR Spectm of paim of cnmpflunds are compamd halow. For each pair of cnmpc-unds, briefly Explain the diffemncesnhsewed in the stretch fraquancics. In each case. Mme specific effect that is must important for your explanaticrn. {a}:oc (2:0 str 1:585 cm'1:0C:D-str ITDE hm‘1 Hon; mfifia emigflflm Lka-f % lmo EWWLEJ Mt | hffim a}; flu M [email protected]/%\?H . RH mAij AH (1:0 511" 17'25 cm" C=U Sh’ 1591 cm'] 09 I? (9 l nfiiWSW‘JUwDUAMEfM J’WH ta rfis’amwmz with 3h AMBAR- RNA ‘ D 0 (3:0 str 1T1"! cm-l (2:0 511' mu Ian-1‘1 ‘39 MILE/c kw; \ggdsS flush-J M {NEW fiom gm msnttfihw am Wu; 4. {10 pts.) For the synthesis of triphenylrnethano] [trityl alcohol), the Grignard reagent phenyltnagnesiurn bromide was reacted with henaophenone in anhydroUs ether. After reflux, this reaction mixture then contained excess Mg metal, unteaeted starting materials, insoluble product. side products and by-produets. This mixture was then treated as follows: 1. Upon cooling, 5 mL water was added. Then dilute HCI was added. 2. The aqueous and organic layers were separated in a separatory funnel. the organic layer was extracted with aqueous sodium bicarbonate. 3. The ether layer was left to stand over anhydrous sodium sulfate. 4. The ether 1aras evaporated off and the remaining solid was tritttrated with petroleum ether. 5. The product Was recrystallized from pet. ether and ethanol. {a} List the structures of all of the compounds that are expected to be present in the reaction mixture before the work-up steps 1-5. a _ a . a W. a? @w) M) @149. wn ms :3 Kb)" Draw a'flbw diagram listing all ofthe starting tefials, products and lay-products 'that'are'preseni before each step, and indicating how they are all ted andior are separated out by each of these five steps. Continue on tlte next page, if necessary. His-Oi H ti. o ' l as (9 DH) W5 )Br} @J "J @[email protected]}_R%QIJH&) 0 (Jr tmpw‘kei H.523} 2' Remarks-n 9- Minkkxm 5. fi {6 pts.) An unknown oompound gave the TR spectrum, the proton NMR spectrum and the protonr decoupled HEM speetmm shown below. {a} Draw a structure in the answer box provided that is consistent with the given spectral data. (tram the most inipofiant peaks th'the IR speetrum.‘ [e] Assign, the oroton-l'xfl‘vfl?~ spectrum, by Writing a letter matching the ones shown in the proton-MAR spectrum next to aagh type of proton in your stt'uotute. (at—3) ANSWER: . Elmo" .' I' innllnmum'l‘l IIlIIIlImli-‘llIIIIlIIllIl::II:flIII|'IIiI!Il--Il E E _ “a ll lllll II II I. lllllllllllllll llllllllllllllllIIfl-I III illlll Mllol ‘- I'l'l' Ililfllfl “m“ fawn ...
View Full Document

{[ 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