MidQuarter Exam 1 Key - CHEM 224 Sum‘ 2011 MidQuarter p....

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Unformatted text preview: CHEM 224 Sum‘ 2011 MidQuarter p. 1 K 2 sec The scores on this test (145 pts) will be prorated such that the highest score given is 120. (08) 1. Rank the compounds shown below as Brensted acids (relative HJr donating ability). Use the following scale: 1 (the strongest acid) to 4(the Weakest acid). OHCCHZCOZCH3 EtzNH CH3COCH3 H20 ova er 3 ft: A- ' -32.- i (20) 2. Fill in missing reagents, starting materials, and/or products in the following synthetic transformations. Some arrows may require more than one step. ‘\ Pt OWV reduced; erm: HQ Byts (HCLL (08) 3. What product (include the deuterium incorporation expected) would result from: O I O 0 0 . \ ’ . Na 02> D l o $ . / c... ____> J >91 D 7 3 D204: D ‘ D D A O :3: . D D 7 . O (9 ® \ D i . C etc ‘ ,Df/‘D CHEM 224 Mithr p. 2 Kg 2 sec (12) 4. Provide the steps required for converting propanoicacid to methyl propyl amine. There are a number routes possible, you only need to come up with one of them. ' (l3) 5. The carboxylic acid shown below undergoes decarboxylation when heated in an inert solvent. This also happens rapidly when the compound is put in boiling water at pH 3, but does not happen if the pH is adjusted to basic values (pH > 8). Rationalize these observations and provide an electron pushing mechanism for the decarboxylation reaction. 0 O coZH CKKK , at (A4 72> + e H‘\O. H C O O ' . OR} ' o I i m COZ #0 dad gkg/ H (p {7/ l _ Quit: V {:5 k” I form ' él/k aft/x?“ jag—{E I (13) 6. Provide unambiguous names for the three structures drawn below. q CL (LL 14‘ %VO\CH(QH3)L LutCN I CH3 0 . is m zzpdlchlombutanoabt I v p a 4 of 7 ,‘ oic kLL‘ca :Yd (Es-Er Mmer'Me-il/j( awoakicrm ’ML @ I p + i ‘ iimns-Z-vij\ do an AflQ. q 3 1 l (.2 Car chip—En: \e/ 3'W‘th—jl'2'bu‘i76npjl chlm'zcla/ . dc Add abilmndb/ CHEM 224 Mithr p. 3 Kg 2 sec (12) 7. Structure elucidation from spectroscopy data. The unknown has the molecular formula C5HgO based onits mass spectrum. The IR spectrum shows an intense absorption in the 1700 —‘ 1730 cm'1 range and has C-H stretches that are observed at > 3020 cm"1. The mass I spectrum does not have a peak at m/z = 83 amu. The compound is transparent to UV light, 7» > 210 nm. - Derive a structure. If you can’t get a complete structure, indicate the structural conclusion that can be drawn from each spectral observation. 4) CsHaO ‘12; , a) siceH ii :3; w a o t 0 A) mot: cogugeteé //\/“\ Beard/v (2er Lou/1A Me Meal/um 91ft; Si’WiC MAX (06) 8. Whichb if any, of the following compounds would be useful as a sunscreen agent? Circle your answer(s) say “NONE”. O . \ :EJEW -‘rt “NONE 01%" +ép’rs (06) 9. Provide an accurate sketch of the “molecular ion region” of the mass spectrum of C6H4BrCl. i 33 ‘72s . a I ~ 79 :00 _ M+Z GWF 3.5 , ' ' ' peak, 3E5 «90 = M 37/ ' * V E \ CHEM 224 Mithr p. 4 \ sec (06) 10. The ketone shown below was dissolved in teIt—butyl alcohol containing an excess of ethyl bromide. A solution of t—BuOK (one molar equivalent relative to the amount of ketone) in t- BuOH was added all at once. What product will be formed? {Bub-fl M 0 ~ +3a0l/ 0 6f“ / 4 +50 17 (12) 11. Come up withascheme for the synthesis of the amide shown below. In your scheme, all of the underlined _C_1_ ’s must be derived from ethyl bromide. , 0 cm Cflchz Br ~———% .Ct‘awz CN QHngz-g-NHQHngs 4r .. i 4/ a! ,: ' CH CH CO H ‘a T V 3 z 2 \soctZ v ’COZH I16 JCS? JL‘CCesS 0H} + rCOCL (08) 12. Shown the expected products by writing a balanced equation. . 0 ~ -_ ?@ @..- (J7 4., LLg(i-pr)Z___> 1 LtocH3 HNéP’)L 3 I (07) 13. The two schemes shown below were suggested by former CHEM 224 students. Provide a critique of these answers: is there anything wrong with the students’ suggestions ? . o i .A. /\/CEN 1' EtM-qBr /\/‘5\/ 0K 3/9?!” _ Ego —-60° ' 3“ wad/(J cm 710 4/60éa/ 2. [-120 f 2 k . O 1 /° 3-“ - ———————> H H“ a' 0/ - EtoH “" ‘3’” 3 _ Soil/emf amides mare sflbéz, Wan/l @5 4g53 own/30 m0 CHEM 224 Mithr p. 5 _____ we Kg sec (14) 14. The two nitrogen-containing aromatics shown below can be protonated. Conditions that work for this are shown below. ' .. H ~ « N\ 10% CH3C02H in ‘ "g9 (N? C. —————-—> 0" \n Hw_ \w Em Mb . > ,7 \A . . . H V \ 40% st04 in \ M D. . T I + \2 NH 1 N/C 2 . H 1 Hz + H zpp ;;fl;w 3Ft\ The solvent shown for C. does not work for D. Explain. w: WVOWA¥ém 1 (D deé‘iflQZIDaromAHcifi W 3, Mod bAStC 5M {*5 Cjci 0‘ M Show (after the appropriate arrow) the structures of the conjugate acids obtained from the two compounds. » Provide a resonance rationale for the protonation site you chose for each. A + [a +l/7/ c Hg; é‘t ( Ni) I / , ‘ ii > H L 4% 4. MC) MOC @0551 W SJLKflVH 3 MA ...
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This note was uploaded on 01/19/2012 for the course CHEM 224B taught by Professor Andersen during the Summer '11 term at University of Washington.

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MidQuarter Exam 1 Key - CHEM 224 Sum‘ 2011 MidQuarter p....

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