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Unformatted text preview: Return my exam in class Return my exam In Clark 278 NAME by S I'M A HOUR EXAM ill 1. (13} a. (10) Below is shown the 1H NMR spectrum given by a compound having molecularforrnula CEHmO. Write the structure of the compound that gave this spectrum. b. (3) By drawing lines from He in your structure to the peaks in the spectrum, assign each peak to H's appearing in the structure you drew which would reasonany give rise to that peak. CsH1so dam; 3‘61'01L0‘H FO “DDIO Sloth”:- malcohtl 6, parts per million (ppm) 2. (14) On the scale provided. draw the predicted 1H NMR spectrum for the hydrogens in 1,1-dimethyl- 1,4-butanediol for which the structure is given below. Be sure you represent correctly the number of peaks, the 5 value expected for each peak, the relative sizes of the peaks, and the splitting pattern expected for each peak A TAELE OF 1H CHEMI AL SHlFT lNFfllfiMATION IS PROVIDED AT THE END OF THE EXAM. {Mot WLWL' "m ofilsis I. as” ‘ a Jiffl 3.“! l5 L5 L2. 3 1m Id. L2, 6 0H 15 { 2A4. 15 wet 2H 2H 6: 1“ L10 5 5W2- chins’e 9H3 HO-CHZCHZCHz-C-OH_ , 0- 5-5 3-4 l-S LS daft“ is (We l | | l | | | | 5 1D 9 B "I B 5 4 3 2 1 l] i 8. parts per million (ppm) i l i '2. i . l 1’ 3 I Hour Exam Ill (3). Chemistry 301. Spring 20012 Page 1 of 5 pages 3. (12, 4 each) Below are shown the structures of nine compounds. Three of the nine compounds gave the IR spectra appearing below the structures. In the space provided on each spectrum. write the letter corresponding to the structure of the compound which most likely gave that spectrum. (Six structures will not be used.) A TABLE OF CHARACTERISTIC IR ABSORPTIONS IS PROVIDED AT THE END OF THE TEST. CH \3 _ CH30H2 H A_ ICHCHQOH a. CH3CHZCH2—Czc-CH3 0. 20:0; CH3 H CH3 0 9H CH3 3 1:1) \ "h. D. c:1-ISCH2—‘l3~cH2c1-l3 5, {CH-CHZ’ 0H F. CHacHZCHZCHz’C‘t-l GHgCH3 CH3 . 0 CH 11 CH3CH2 OH; I 3_ ,C~ G. \C:C/ H. CHa—cE—C=C_H J. CchHch2 CH3 H/ \H CH3 . I u 'r I I 13333 1173.7T' : _- 1 1717.4 1235.5 727.3: ' " ' 77314223 ' 1235.5 5913 “'"l‘" ‘l NICOLEI' 208)! PM?! .I a II I IL}:- V I II ¥+--+L—.—i—.—. . . . _ . 'i 3 2333.7 13737 1317.4 ‘ 2733.0 1233.3 33¢.o T. :5 NIOOLEI' 205)! PH“ II 1‘ II ‘I 11' ll II 21 a II _,l. 5 _ L..er I u . L'! 1 i . ' - - 1 i g 3323.1 1337.5 2337.3 1247.4 313.5. 5'! 14733 13413 3393::g,-. '..__';"tt.:_:”t'. 'l ' ‘. "'- 1m 1m ll IIIAVBIIJIIBEFIE NICOLET 233x l-‘r-tR Hour Exam III {a}. Chemistry 301. Spring 2007. Page 2 of 5 pages 4. (12) On the line provided below. draw the predicted 13C NMR spectrum (‘H-decoupled) for the carbons of 1-bromo-3-pentanone for which the structure is given below. Be sure you represent correctly the number of peaks and the 6 value expected for each peak. Draw a star beside each signal in your spectrum that would be expected to appear as an upright line in the DEPT-135 spectrum of this compound. A TABLE OF '30 CHEMICAL SHIFT INFORMATION l8 PROVIDED AT THE END OF THE EXAM. SHOW HOW YOU ESTIMATED THE CHEMICAL SHIFTS YOU USED. 0 0 ll Lt CHacH§;::CHZCHzBr =' tkfifidj 0 5H36H3 '1 .56 Ln, 2.! Q to (9 U0 [9 a) 9 met: I so “ml :Towwc 7 2" [1 Lo :vax'tlr ‘17 17 5|: lll Illlllllllllllllllllill 220 210 200 19C! 180 1?0 160150 140 130 120 110 100 9|] BI] 70 60 50 40 30 20 10 D 6. ppm 5. (5) One of the five isomeric compounds having molecular formula CsH11Br for which structures follow gave the fully decoupled 130 NMR spectrum and the DEPT-90 and DEPT~135 spectra that appear below the structures. Circle the structure that best fits these spectra. Br I CHsCszféin-Br OHS—clz—CH20Ha CH3 9H3 CHg‘C—CHzBr CH3\ (EH3 CHSICH—CHZCHz-Br 0+) on 0*? DEPT-135 I I 200 MLI let-t; 0d DEPT-90 l 200 11.2 C H Br 21613.4 5 11 CDCIa 41.0 36.8 J I m lmlm m, M 200 0 (TM 3) Hour Exam “Hal, Chemistry.r 301‘ Spring 200?. Page 3 of 5 pages 6. (‘10) Name the compound having the structure shown. In your name. be sure to include the correct stereochernical desi nation for an chiral center usin the RB s stem. IN NAMING A CHIRAL CENTER. YOU MUST SHOW THE PRIORITY (highest priority = 1 or a) THAT YOU HAVE ASSIGNED TO EACH GROUP. THE CONFIGURATION YOU GIVE MUST BE CONSISTENT WITH THE PRIORITIES YOU ASSIGNED. DO NOT ASSiGN PRIORITIES TO THE GROUPS ON ACHIRAL CARBONS. A periodic table is iiovidii at the end of the test. 2, COLIN ) F\ (7):?H3 3H: “t a- HHOYD (C 2 d 0’13 f t. 7;E’CH3 '1' l' A @‘lz'CHz—C 7-..”th (3)“ Li“ widow‘qu 7 * ail—dw- Ifl $ at Bran/b “.I.( 2,, 2- HCWMHDJ'L Rum/7» Wm I, (g) Br 11) C 7. (22) The compound 2.3—dichloro-2.3-difluorobutane is related to common refrigerants. A Fischer projection of one of the two enantiomers of 2.3-dlchloro-2,3-difluorobutane is shown below. In part a of this problem. three structures are given that represent possible stereoisomers of 2.3-dichloro-2.3-difluorobutane. This problem will take you through the process of determining the stereochemical relationship of each of the three structures to the given enantiomer of 2.3-dichloro-2.3-difluorobutane. CH3 C; (I; 2.3-dichloro—2,3=difiuorobutane CH3 a. (15. 5 each) In the space below each of the following structures, draw a Fischer projection of the same structure that has been arranged with the two OH; groups at the top and bottom so that it can easily be compared with the structure that is given above. F CH3 3 A C! 3/ Cl,“\ /F a C1 F ' CH3 1‘ -: F CH3 / l’ } 01 F F- ’kcn J CH3 M M b. (6, 2 each) Beneath each of the structures you drew in answering part a above. tell whether your structure represents the identical compound as was given for 2,3-dichloro-2,3-dtfluorobutane at the beginning of this problem. Is the enantiomer of that compound, or is a diastereomer of that compound. REMEMBER: Different conformations of a compound that can be interchanged by rotations around singie bonds are not considered to be different compounds. 0. (‘1) One of the structures you drew should represent a mesa compound. Circle the structure you drew that represents a mess compound. Hour Exam lllta}. Chemistry 301. Spring 200?. Page 4 of 5 pages 8. (12) Below are given the IR and the 1H and 13C NMR spectra of a oompound having molecular formula CsHa. In the space provided. draw the structure of the compound. If you are not able to determine the entire structure. show whatever partial structures you are able to determine. REMEMBER: the peaks marked with an asterisk {*J on the peak labels provided with the 13C NMR spectrum were found to point up in a DEPT-135 spectrum. mu azalilufingruu: u I ES I tlad (‘r-Jllili .. . -. ..: :'I;_1_;___5,J__;'1f.;..= :: 3303.9 1450.1 1255.0 . 295m 1331.3 531m 1L. _- 211911 1323.1 ——i _ ' ' | - l1. .. l Hour Exam Ima'). Chemistry 301. Spring 2001a Page 5 of 5 pages I: I quaxum ...
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