1NAME _______________________ ID # _______________________ ORGANIC CHEMISTRY I (2301) 9:30 – 10:20 am, July 21, 2011 Exam 3 Form A If you want to pick this exam up on Tuesday in class (in public), please check the box on the right: If you do not check the box, I will not bring your exam to class on Tuesday, and you will need to pick up your exam in private from Chemistry department staff in 115 Smith beginning Tuesday, July 26th. Exams that are not picked up within two weeks will be disposed of. A periodic table and a chart of reaction conditions are attached to the back of this exam as aids. Otherwise, you are not permitted to use any other materials (including notes, books, or electronic devices of any kind). Right now, write your name at the top of this page, and fill in the bubbles on the multiple-choice answer sheet for your name and your 7-digit student ID number (in columns 1-7 of the “Identification Number” section, as shown at right). When the exam begins, also write your name at the top of page 5. You may use pen or pencil. However, re-grades will be considered only for exams completed in pen. Please write your answers in the bubble sheet for the multiple choice portion of the exam, and in the boxes/spaces provided for the written portion. If your answer is not in the appropriate space in the written portion (say, for example, it’s on the back of the page), draw us an arrow and/or note telling us where to look.2Multiple-Choice Problems Please answer these problems on the bubble sheet. (4 pts each) Each of the reactions below is drawn with two possible products, marked (a) and (b). If one of the two products predominates, answer with the letter corresponding to the correct product. If the two products are produced equally, answer (c) BOTH. If neither product would result from the reaction, answer (d) NEITHER. 1. 2. 3. 4. CH3OHNCCH3CNHOOH HHCH3 BOTH (equally) NEITHER 1. NaCN 2. H3O+ a. b. c. d. OHHHH3COHCH3HH BOTH (equally) NEITHER 1. BH3•THF 2. H2O2, OH- a. b. c. d. BrCH3OOOOBr BOTH (equally) NEITHER HBr a. b. c. d. H HCH3CH2CH3CCCH3CH3CH2 BOTH (equally) NEITHER Na, NH3 a. b. c. d. CH3CH2CH2CH2CH335. 6. 7. 8. Pt/H2 (D = deuterium, heavy isotope of hydrogen) CH3HHDCH3HHD BOTH (equally) NEITHER a. b. c. d. Br2 h BOTH (equally) NEITHER BrBra. b. c. d. CCHCH3BrBrH3C CH3Br Br BOTH (equally) NEITHER HBr (excess) a. b. c. d. BOTH (equally) NEITHER a. b. c. d. C CH3CH3CCH3CH3H3CCH3OOH3CCH3CH3H3CH3CCH3OOHH3CH3CCH32 KMnO4 H2O, pH 74(4 pts each) Each of the reactions below is drawn with two possible reaction conditions. If only one of the two reaction conditions would generate the given molecule as the major product, answer with the corresponding letter. If both sets of conditions would accomplish the reaction, answer (c) “BOTH”. If neither set of reaction conditions would succeed, answer (d) “NEITHER”. 9. 10. 11. (3 pts each) The chemical structure of isopentane shown on the right has three C-H bonds labeled. 12. Which of the three bonds has the smallest bond dissociation energy (BDE)? 13. Which C-H would be most likely replaced by a C-Cl in a radical chlorination with Cl2 and UV light? BOTH would work NEITHER would work mCPBA H2OKMnO4 H2O/-OHa. b. c. d. HCH3H3CCH3H3CHHOOHCCCHCH3HHH3CHHHb c a BOTH would work NEITHER would work 1. KMnO4 KOH,  2. H3O+ O3, H2O a. b. c. d. O OOH HOCCHHOBH21. 2. H2O2 NaOH BOTH would work NEITHER would work HgSO4 H2SO4 a. b. c. d.5 NAME _______________________ Scoring: 14. _________ / 20 16. _________ / 15 15. _________ / 15 Total Score: _________ / 50 14. (20 pts) For each of the reactions shown below, draw a mechanism that explains how the product is generated from the starting material. In your answer, make sure that you: - Draw each step of the mechanism separately; - Use “electron pushing” to show where the electrons in each step go; - Illustrate stereochemistry where appropriate; - Use only the molecules that you are given; do not invoke reactants or solvents that aren’t in the problem. H3CCH3BrHHH3COH3CCH3HHMechanism: Br2 CH3OH6 15. (15 pts) Draw the missing reactant or product in the empty boxes. For products, give the predominant, most favored product. Illustrate stereochemistry in your answer where appropriate. For reactions that yield multiple enantiomers, draw only one enantiomer in the box, and include the note “+ enantiomer”. (NBS) + trace R• HHCH3CH3NOOBrOH CH2CH3H3C HClOOOHan alkene (mCPBA) Cl ClClH3CCH3CH3HHClClH3CCH3CH3ClMechanism: + +7 16. (15 pts) For each set of starting materials and products shown below, propose a multistep synthesis. In addition to the molecules shown, you can use any reagents and reactions we’ve learned about in class. You might discover multiple answers to this problem; draw only your best (one) synthetic route. Feel free to draw an incomplete route—we will give you partial credit where we can. HHCCHH1. O3 2. (CH3)2S HHand HOCCHExam 3 Chart of Reaction Conditions Reactions to consider from Ch. 6-7 (Exam 2): Acid-Base, SN2, SN1, E2, E1 Cl2 or Br2, h HBr 1. Hg(OAc)2 H2O or ROH 2. NaBH4 H2SO4 H2O1. BH3•THF 2. H2O2, OH-Br2 Br2 H2O or ROH ClOOOH(mCPBA)mCPBA H2O KMnO4 (cold, dilute) H2O, OH- 1. O3 2. (CH3)2S Pt/H2(g) NaNH2 Na NH3 HgSO4 H2SO4 BH21. (“Sia2BH”) 2. H2O2, NaOH 1. KMnO4 KOH, 2. H3O+ OOOOHBr (benzoyl peroxide) Pd, BaSO4 H2(g) (quinoline) N(NBS) h or AIBN NOOBr1. O3 2. H2O KMnO4 H2O, pH 7Periodic Table of the Elements Chemistry Reference Sheet California Standards TestSodium22.99Na11 Atomic numberElement symbolAverage atomic mass* Element name Hydrogen1.01H1Lithium6.94Li3Sodium22.99Na11Potassium39.1019K Nickel58.69Ni28 Rubidium85.47Rb37 Rutherfordium(261)Rf104 Molybdenum95.94Mo42 Germanium72.61Ge32 11A 22A 1234 77B 111B 122B 133A 166AKey 8 567 98B 10 144A 155A 177A 188A 33B 44B 55B 66B Copper63.55Cu29 Cobalt58.93Co27 Helium4.00He2 Boron10.81B5 Carbon12.01C6 Nitrogen14.01N7 Oxygen16.00O8 Fluorine19.00F9 Neon20.18Ne10 Aluminum26.98Al13 Silicon28.09Si14 Phosphorus30.97P15 Sulfur32.07S16 Chlorine35.45Cl17 Argon39.95Ar18 Calcium40.08Ca20 Scandium44.96Sc21 Titanium47.87Ti22 Chromium52.00Cr24 Iron55.85Fe26 Zinc65.39Zn30 Gallium69.72Ga31 Arsenic74.92As33