ORGANIC CHEMISTRY II (2302) 8:00 8:50 am, July 23, Exam 3

Transcription

1 AME ID # RGAIC CEMISTRY II (2302) 8:00 8:50 am, July 23, 2015 Exam 3 If you want to pick this exam up Monday 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 Monday, and you will need to pick up your exam in private from Chemistry department staff in 115 Smith beginning Tuesday, July 28 th. 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 an aid. therwise, you are not permitted to use any other materials (including notes, books, or electronic devices of any kind). Right now, write your name and student ID number at the top of this page. When the exam begins, please write your name at the top of the next page. You may use pen or pencil. owever, re-grades will be considered only for exams completed in pen. Please write your answers in the boxes/spaces provided. If your answer is not in the appropriate space (say, for example, it s on the back of the page), draw us an arrow and/or note telling us where to look. 1

2 AME Scoring: 1. / 6 4. / / / / 16 Total Score: / (6 pts) Each of the carbonyl-containing compounds below is acidic, and can be deprotonated to form an enolate anion. For each pair, circle the stronger acid. which is a stronger acid? (circle one) which is a stronger acid? (circle one) 3 C or 3 C or 3 C 2. (20 pts) 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, circle those conditions. If both sets of conditions would accomplish the reaction, circle BT. If neither set of reaction conditions would succeed, circle. Circle one answer only. 3 (1 equiv) 1. a 3 (1 equiv) 2. PPh 3 Br 2 BT C 2 I 2 Zn(Cu) C 2 2 K t Bu BT 2

3 C B Pd(Ac) 2 PPh 3 Et 3 Pd(Ac) 2 PPh 3 - C BT 3 C (excess) a (excess) a 3 C BT 3 C a 2 a BT 3. (16 pts) Each of the reactions on the next page is drawn with two possible products. If one of the two products predominates, circle that preferred product. If the two products are produced equally, circle BT. If neither product would result from the reaction, circle. Circle one answer only. 3

4 2, 2 BT (equally) 1. a 2. Ts BT (equally) 1. LDA, -78 C 2. Br BT (equally) ad D 2 BT (equally) 4

5 4. (24 pts) For the reaction 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; Use only the molecules that you are given; do not invoke reactants or solvents that aren t in the problem. I have drawn one intermediate in the mechanism for you, but you will still need to push electrons for steps to and from that intermediate. - 5

6 5. (34 pts) For each of the reactions on the following pages, fill in the empty box corresponding to reactants, reagents, or products. Give only one answer in each box. For reactions that you expect to yield multiple products, draw one major product. For reactions that yield multiple enantiomers, draw only one enantiomer in the box, and include the note + enantiomer. Br 2 a 1., Ts (trace) 25 C Br a (workup) carbonyl-containing starting material used in excess? YES or? (circle one) carbonyl-containing starting material used in excess? YES or? 6

7 2 PCy 3 Ru PCy 3 a + monocyclic starting material monocyclic starting material 7

8 Exam 3 Chart of Reaction Conditions Br 2 FeBr 3 2 Al 3 2 S 4 3 Sn or Fe / 2 2 S 4 S 3 KMn 4 -, 100 C 1. a 2 2. CuC or 3 P 2 or CuX or R Al Pd-C RMgX R-X (R = alkyl) Al 3 or FeBr 3 Li hexane Zn(g), / 2 Mg Et K, R 2 CuLi RLi a 2 Cr S R-X 3. Li 1. ab LiAl Li (Grubbs catalyst) (S) Bu 4 + F - a 2 S 2 (& pyridine, usually) C 3 KtBu LiAl(tBu) 3 C (DCC) 1. a 3 2. PPh Ag (C) 2 1. PPh 3 2. n-buli 3. R R' PhC 2 Br Ag 2 ( ) 3 Si {TMS}, or TBDMS; Et 3 or imidazole C (EDC ) (or - ) Pd(PPh 3 ) 4 a C 2 I 2 Zn(Cu) Al Al (DIBAL-) + B 3 1. I (excess) 2. Ag 2 2 RC a(ac) 3 B or ab 3 C Pd(Ac) 2 PPh 3, Et 3

9 Gold Periodic Table of the Elements Chemistry Reference Sheet California Standards Test A 1 ydrogen Li Lithium 6.94 a 11 Sodium K Potassium Rb Rubidium A 104 Rf Rutherfordium (261) 42 Mo Molybdenum Atomic number a Element symbol Sodium Element name Average atomic mass* Cs 55 Cesium Fr Francium (223) Be 4 Beryllium 9.01 Mg 12 Magnesium Ca Calcium Sr Strontium Ba 56 Barium Ra Radium (226) 3 3B 21 Sc Scandium Y Yttrium La 57 Lanthanum Ac Actinium (227) 4 4B 22 Ti Titanium Zr Zirconium f afnium B 23 V Vanadium b iobium Ta 73 Tantalum Db Dubnium (262) 6 6B 24 Cr Chromium B 43 Tc Technetium (98) W 74 Re 75 Rhenium Tungsten Sg Seaborgium (266) 25 Mn Manganese Bh Bohrium (264) Key 8 26 Fe Iron Ru Ruthenium s 76 smium s assium (269) 9 8B 27 Co Cobalt Rh Rhodium Ir Iridium Mt Meitnerium (268) i ickel Pd Palladium Pt Platinum B 29 Cu Copper Ag Silver Au B 30 Zn Zinc Cd Cadmium g 80 Mercury A Boron A B 5 Carbon Al Aluminum Ga Gallium In Indium Tl Thallium Ge Germanium A C 6 itrogen Si Silicon Sn Tin Pb 82 Lead A 7 xygen P Phosphorus As Arsenic Sb Antimony Bi Bismuth A 8 Fluorine S Sulfur Se Selenium Te Tellurium Po 84 Polonium (209) 18 8A e 2 elium F 9 e eon Chlorine Br Bromine I Iodine At Astatine (210) 18 Ar Argon Kr Krypton Xe Xenon Rn 86 Radon (222) * If this number is in parentheses, then it refers to the atomic mass of the most stable isotope. Ce 58 Cerium Th 90 Thorium Pr Praseodymium Pa 91 Protactinium d 60 eodymium U Uranium Pm 61 Promethium (145) p 93 eptunium (237) Sm 62 Samarium Pu 94 Plutonium (244) Eu 63 Europium Am 95 Americium (243) Gd 64 Gadolinium Cm 96 Curium (247) Tb 65 Terbium Bk 97 Berkelium (247) Dy 66 Dysprosium Cf Californium (251) o 67 olmium Es 99 Einsteinium (252) 68 Er Erbium Fm 100 Fermium (257) Tm 69 Thulium Md Mendelevium (258) Yb 70 Ytterbium o obelium (259) Lu 71 Lutetium Lr Lawrencium (262) Copyright 2008 California Department of Education