322as05_final_key

322as05_final_key - \qz i CHEMISTRY 322aL Please FINAL EXAM...

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Unformatted text preview: \qz i CHEMISTRY 322aL Please FINAL EXAM Print Last Name MAY 4, 2005 First Name USC ID TA's Name Grader (1) (45) __ (2) (20) Lab Day & Time (3) (20) (4) (30) (5) (15) (6) (20) (7) (15) __ __ (8) (10) __ _ (9) (25) __ __ (200) first letter of last name M. I will observe all the rules of Academic Integrity while taking this exam. Chemistry 322aL Final Exam 3 Z r: (1) (45) Complete the chemicmelow by providing the organic product or products (as requested) within each box. You do not need to show byproducts of the reactions or any mechanisms. Show or describe stereochemical details in the products wherever they are important, including a racemjc form of a chiral product. "Workup" means adding water and bringing the solution to neutral pH. Name (i) NaNHZ/liq. NH3, -33°c (A) CH3CH2CH2C ECH (ii) CH3I CH 5C H LQHLCE QC H 3 (B) CH CH CH CH Br + CH COK ~ ._ 3 2 2 2 ( 3>3 t-butyl alcohol CH'3CHZCH ' QHL major product only decolorizes cold KMnO4 solution HCl/ ZnCl C C product does not decolorize Brz/CCl4 and is not soluble in conc. HZSO‘l N acetonitrile + 'C CHZCHZCH3 -( ‘g (100% ee) flaw/1m N Mr. (100% ee) H- C56 ° (i) NaH (E) (mg/[M <1» CHsI CHZCHZCHZOH (100% ee) (100% ee) __——__l 3% Chemistry 322aL Name Final Exam x (1) Contd. H3 CH3 (F) (i) cold, conc. H2504 /\(\OH (ii) H20, heat \\/ 0” CH (G) 3:0 /CH3 cold KMnO4, KOH H C‘}; H20 _ + I HOO K KOH 100% ee (5) THE H20 OCHZCH3 + HBI‘ two organic products one has protic H H q (I) + SOC]2 G product does not dissolve in cold, conc. H280 3w Chemistry 322aL /T Name Final Exam (1) Contd. H (K) CH3QCH2CH2CH3 + Br2 hV CH3 heat _ amine base (L) HC=CCH2CH20H + (CH3)3SiCl (i) Hg(OAC)2/THF,H20 (M) CH3¢HCH=CH2 m» CH3 (ii) NaBH4, NaOH CH3CH2\ /H 03H (N) H/C=C\ + M32+___. --Q-—C-—‘ E4 CHZCH3 CO2 2 ethanol 1 fl Wet ' product of alkene "" a; mum“ \nuT OK {’C \C Mofi' \1\d?C‘-T¢d Chemistry 322aL -5- Name Final Exam (2) (20) Answer the following questions. (A) (8) Provide resonance structures, as requested, for the following chemical Species in the boxes below. Your structures must show all valence-level electrons and use the dash notation for covalent bonds. Be sure to show any formal charges immediately next to the atoms on which they reside. Your structures should obey the octet rule. (i) the formate ion, HCOZ- two resonance structures (ii) diazomethane, CHZNZ . M 0+ 0.5 two important resonance structures (B) (6) According to valence shell electron pair repulsion (VSEPR) theory, what is the geometry around the bolded central atom in each structure below? Write your choice of linear, trigonal planar or tetrahedral on the line below the structure. m 1 l +d—rmlualc—n.\ +VT§0 NA plgmr 4* \- wl N V“ (C) (6) Indicate whether each compound below is chiral or achiral on the line below the structure. Identify all stereocenters in each structure with an asterisk(*). A stereocenter is defined according to the usage in our text and the lectures. l C 3" OOH \“ H H‘ [a M ~18 9? Cl H H CH2=CHCHC1CCH3 1 A CH3NH2 CH38CH3 (CH3)3(}§ : COOH H\ M Ck? ro~\ ads? r«\ C)“ r c\ got/1442450“ (canal, weé i'CYD) Chemistry 322aL -6— Name Final Exam (3) (20) Answer the questions below. (A) (4) Provide the complete IUPAC name of the compound inside the box to the right on the line below the box. (B) (4) Provide the complete IUPAC name of the compound inside the box to the right on the line below the box. Hint: Note it is chiral. (C) (4) Provide a structure of the most stable 3 H c (C “Q conformation of tmrzs-1~t-butyl-3-methylcyclohexane inside the box. H (D) (8) Identify the pairs of structures below as constitutional isomers, enantiomers, diastereomers, or the same compound on the line below each pair. COZH H3 (EH3 cH3 H—T Cl H—' | C1 CH CH CHCH CH CH(CH ) CH CHCH CH HCH 3 2 2 2 3 2 3 2 2C; 3 CH3 COZH CHZCH3 Sap/Ac Comgoucmgl examkfiowx—Q C H H3 C6H5 6:225 \ =<H Hfo C 3 H C 3 CH3 ‘ " ' ' Atmsficcowrs dfms+cuom<v3 Chemistry 322aL Final Exam 2 ,Zd( (4) (30) Circle the co rect answer for each question or statement below. -7- Name (A) The correct molecular formula and U-number (degrees of unsaturation) of the structure below are (circle answer belo M C101‘112O 5U (CIOHIOO 6U ) I \ (3101—1140 4U ClonO 5U / (B) The numbers of valence electrons in each of the structures below are (circle answer below) - + C2H3 CH5O I 10, II 16 I 11, II 16 I H I 12, II 14 l I 12, II 15 (C) Among the following organic compounds, intermolecular hydrogen bonding is important in the condensed phases of (circle answer below) CH3CHZOCH2CI-I3 CHBCHZCHZCHZOH I H only 11 11,111 and IV CH3CH2CH2(CRH CH3CH2CH2NH2 II and III < II and IV R > 111 IV - (D) The order of acidity (strongest to weakest) among the organic compounds below is (circle answer below) CH3CH2CH2NH2 CH3CH2COOH < II>III>I>IV ) II>I>III>IV I 11 III>II>I>IV III>I>II>IV CH3CH2CH20H CH3CH2CH2CH3 III IV (E) In trans-1,4-dimethylcyclohexane, the lower energy chair conformation is more stable than the higher energy chair conformation in gauche interactions (G) by (circle answer) 16 2G 3G Chemistry 322aL -8 Final Exam (4) Contd. Z fill. (F) In the reaction below, the dominant mechanistic pathway will be (circle answer below) I?" I CH3CIa12QCH3 + NaOEt ethanol 5N1 8N2 E1 CH3 Name (G) In the reaction below, the dominant mechanistic pathway will be (circle answer below) N1!“ + 1‘ [email protected] E2 acetone (H) Ozonolysis of a hydrocarbon, C8H14, yields the product (I) below. What is the structure of the hydrocarbon? (circle answer below) CH3CH2§CH2CH2CH2CH2§H E}. U 6/ I I 1 (I) The stability order of the isomeric alkenes (C5H10) below is I /D/ 111 (circle answer below) I>II>III III>II>I II>I>III (I) The maximum number of products separable by physical methods, and their stereochemical features, produced in the monochlorination of 2-methylbutane are C1 (circle answer below) CH, irradiation 4 roducts 3 chi 1 1 achiral roduct ' a1 2 achira products 3 chiral Zachiral Chemistry 322aL -9- Name Final Exam (4) Contd 2 ‘64( A (K) Which of the followmg reactions of (Z)-2—butene 15 (are) stereospec1f1c syn- additions? (circle answer below) CH3¢CH3 I>II>III II>I>III (N) Overall anti-Markovnikov addition to propene is observed with which of the following procedures? CH3CHZCH2 antl-Markovnikov (circle answer) B and C (O) In which addition reactions of alkenes is a carbocation intermediate clearly involved? HVHZO hydroboration oxymercuration epoxidation with peroxyacid hydration A B C D (circle answer) A and C A and D A and B Chemistry 322aL -10- Final Exam +69 ckcq for first propagating step above. / o 2 —-H :-o—- :—S\(C4lho\ an Dam ow \1(<\8\ _ ~3— in kcal/mol (ii) Calculation of AH0 for second ro a atin ste above. P P g g P an t. m? at: 2~2L—C*<831‘1”‘“/“°‘I ~23] C‘C—\ C\-C_\ in kcal/mol (iii) Calculation of AH0 for net chemical reaction. 0 0 ._ ARC -.~_ w + M 2 ~S +0133 “~13 g hwy (fl KC ml 6“ in kcal/ mol Chemistry 322aL -11- Name Final Exam (6) (20) Answer the following questions about the addition reactions of HBr to isobutene (2-methylpropene) o TlmL ‘1ch \kkMTS‘l'F‘l \3 At‘ltr““’k‘~i lad + K 0‘: fl’x CQVSoCaHOx TmfirMLA/EL*( ##NA~ Mom— anJolc vn‘l-u-ML (Ltd‘K {:5 fiat-ML Explain the regiochemistry of this reaction in the box above. (B) (10) In the presence of peroxides (ROOR), this reaction gives an anti-Markovnikov addition product by a free radical chain reaction. Provide a mechanism for this addition reaction that includes the initiation steps and the two propagating steps. In the box below, explain the regiochemistry of this reaction. RO-OR ——-> '1 R0- ROQQEEr --*>RO+* JV 3" Initiation steps CH1 CH3 ch— Mom SAWB\< ‘gm; PCsQlA‘Cm\ \S ~Fov~~xzd . xplain the regiochemistry of this reaction in the box above. Chemistry 322aL -12- Name Final Exam (7) (15) (A) (7) Reaction of (Z)-2—butene with a peroxyacid in ethanol produces product A. Reaction of A with aqueous KOH yields B. Provide detailed structures for A and B that show stereochemical details. In the shadow box above the arrow for the first step indicate whether that is a syn or anti addition. C4H1002 achiral product ‘ racernic form of chiral product (B) (4) Reaction of (Z)-2—butene with Brz/HZO produces C. Treatment of C with sodium hydride in an ether solvent gives A (same product as above). Provide the detailed structure of C, showing all stereochemical details in the box below. In the shadow box indicate whether the first step proceeds by syn or anti addition. NaH ether solvent A racernic form of chiral product (C)(4) Sketch a plausible mechanism that explains the formation of A from C. Clearly show the reaction with NaH and the stereoclgiical course of the reaction C ——>A. CA Q") Ma (3% :QHE’ \ 5’ .— 'fi> H ‘t Q— Q’ CHSr/IIC —'C\ + N &H 5 (“.3 :1 l + H’K R gr H Er qug/la—wz’ /0\ CR d/dc__ {AH ——v———-> CHatf/dC—_Cfi§‘C—H3 + flag? 3 H Sjyk H A H Chemistry 322aL Final Exam (8) (10) Compounds A a {WA( Name "My \ MC, W!” M stru ural formula of A \/ C HSCHZCD CH3 Chemistry 322aL -14— Name Final Exam (9) (25) Provide reasonable syntheses, as requested below. In Part (A), work two of the three short sxntheses. Part (B) is on the next page. A Table of Reagents lS prowaed in t e Appen ix or your use. You are notli ' ' ' oCH3 (S)~CH3CH2CHCH3 ----------- - - + (R)-CH3CH2CHCH3 41 H \D 5': CH Okla. 2 45¢ C i + CH 500 "A (QWCH CH 0H CH (IVXH a \w s nh—fioxemo 3 s - \‘l’ 0 l I) 3 '3 Q“ C9 (mutt-$044 QHZQHB 2 .3 L 3 (s) («A Silva aSv-l—r-OC M 4w? ’1' LCM—A— Chemistry 322aL -15_ Final Exam CH3CH2CH2CHZBr ‘ ‘ ' ' - - - - - - — - - - -> \ CH CH and any other alkyl halide 3 2 CHzCH3 and needed reagents KO N—‘E BC; $0 Q ~ c c CH CH C 1 CH flC c 7 Q N NH 7 NH C WCHZCHLQECH “33 °‘ It l ‘i a my};qu H3 (n CHACHLBV m 14$ HZ Pal/C Po\§oqc4 (j s or PJL Cu+ Appendix Table of Homolytic Bond Dissociation Energies (kcal/mol) CH3CH2-H CH3CH2-C1 H-Cl C1-C1 C-H -98 C-Cl -81 -103 -58 Table of Selected Reagents HBr H0 H1 SOCIZ PBr3 Brz CH3SOZC1 Hz/Pt Hz/Pd(poisoned) NaBH4 NaNHz NaCN NaI—I NaOEt KOBu-t NaOH Hg(OAc)2 KI KMnO4 O3 BH3.THF H202 (peroxides) (CH3)3SiC1 / amine base MMPP (magnesium monoperoxyphthalate) You may use other reagents as well in your syntheses. ...
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This note was uploaded on 01/30/2009 for the course CHEM 322AL taught by Professor Jung during the Spring '07 term at USC.

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322as05_final_key - \qz i CHEMISTRY 322aL Please FINAL EXAM...

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