/90 /100. Last 4 digits of A number Score. I. Multiple Choice ( /30) II /10. Total score. Note: Periodic table and pka Values are on page 13.

Transcription

1 Chem 2300 Exam 2 October 25, 2013 Name: (first) (last) Last 4 digits of A number Score I. Multiple Choice ( /30) /90 II /10 Total score /100 Note: Periodic table and pka Values are on page 13. 1

2 I. Multiple choice questions. (3 points each). Please put your answers on Scantron sheet. Your score will be graded based only on your answers from Scantron sheet. 1. What is the systematic name for the following compound? 3methyl1vinylcyclohexene 2methyl4vinylcyclohexene 1methyl3vinylcyclohexene 1methyl5vinylcyclohexene 2. What is the systematic name for the following compound? (R)5methylcyclohexene (S)4methylcyclohexene (R)4methylcyclohexene (S)5methylcyclohexene CH 3 3. What is the systematic name for the following compound? CH 2 CH 3 1ethyl1,4cyclohexadiene 1ethyl1,3cyclohexadiene 2ethyl1,4cyclohexadiene 1ethyl1,3cyclohexadiene 4. What is the systematic name for the following compound? cis4methyl3hexene trans3methyl3hexene (Z)3methyl3hexene (E)3methyl3hexene 5. What is the systematic name for the following compound? (Z)2fluoro4methyl2heptene (E)1fluoro4methyl2heptene (E)2fluoro4methyl2heptene (Z)1fluoro1,3dimethyl1hexene 2

3 6. What is the systematic name for the following compound? (E)1bromo1fluoro3methyl1pentene (Z)1fluoro1bromo3methyl1pentene (E)1fluoro1bromo3methyl1pentene (Z)1bromo1fluoro3methyl1pentene 7. What is the systematic name for the following compound? 3fluorocyclohexene (Z)3fluorocyclohexene Cis3fluorocyclohexene (R)3fluorocyclohexene 8. Which of the following compounds have Z configuration (carboncarbon double bond)? O HO I II III IV Cl Cl I, III, IV I, II, III I, IV I, II, III, IV 9. What is the correct order of stability for the following alkenes (most to least)? I II III IV V I>II>III>IV>V V>I>III>IV>II V>I>IV>III>II V>IV>III>II>I 3

4 Based on the potential energy diagram for the following reaction, answer the questions from 10 to 13. HCl II Cl potential energy A III IV B I C V 10. What could best describe the reaction above? reaction coordinate This is a onestep endothermic reaction. This is a onestep exothermic reaction. This is a twostep endothermic reaction. This is a twostep exothermic reaction. 11. Which of the following represents the heat of reaction? A B C A and B III 12. Which represent the activation energy of the ratedetermining step of the reaction? A B C A and B II 4

5 13. Which of the following description is correct? This reaction will lead to the formation of meso compounds. This reaction will lead to the formation of achiral compounds. This reaction will lead to the formation of a racemic mixture. This reaction will lead to the formation of structural isomers. 14. What is the systematic name for the following compound? (R)4bromo2hexyne (R)3bromo1hexyne (S)4bromo2hexyne (S)3bromo1hexyne 15. Arrange these carbocations in order of stability (most to least).? I>II>III>IV III>II>I>IV III>I>II>IV II>III>I>IV I>III>II>IV 16. What could be the possible product for the following reaction? 5

6 17. The second reaction in glycolysis involves the conversion of Dglucopyranose 6phosphate (I) to Dfructofuranose 6phosphate (II) under the catalysis of phosphoglucoisomerase. Which of the following can best describe the relationship between compound I and II? Dglucopyranose 6phosphate Dfructofuranose 6phosphate They are structural isomer to each other. They are diastereomer to each other. They are enantiomer to each other. They are identical. 18. What could be the major product for the following reaction? H major product? 19. What will be the major product in its most stable conformation from the following reaction? H 2 Pd/C product? OH 6

7 20. ominated vegetable oil (BVO) has been used to stabilize citrusflavored soft drinks since Its high density helps the droplets of natural fatsoluble citrus flavors stay suspended in the drink. BVO can be prepared by reacting vegetable oil, which contains unsaturated fatty acid, such as oleic acid, with bromine. Without specifying the R group for the following representative structure of vegetable oil, what will be the products from bromination? I, IV I, II III, IV II, III 21. Which is a diastereomer to the compound circled in the box? I II III IV 7

8 22. Coniine is a poisonous alkaloid found in poison hemlock and the yellow pitcher plant as a mixture of R and S isomers. One method to separate the R and S coniine is by addition of a chiral acid and separation of the salt of diastereomers by recrystalization, a process called resolution. Which of the following acid can be used to achieve the separation of R and S coniine? 23. How many chiral carbons (not chiral amines) are present on Amoxicillin, an antibacterial drug? Which of the following compound is achiral? I II III IV 8

9 25. What are the R and S assignments for carbon 2 (C2) and carbon 3 (C3) of cocaine? C2 is R and C3 is R. C2 is R and C3 is S. C2 is S and C3 is R. C2 is S and C3 is S. 26. Which of the following compound is chiral? I II III IV V 27. Ephedrine in its natural form, known as má huáng ( 麻黄 ) in traditional Chinese medicine, has been documented in China since the Han Dynasty (206 BC 220 AD) as an antiasthmatic and stimulant. What are the correct R and S assignments that match the given systematic name of ephedrine? (1R,2S)2(methylamino)1phenylpropan1ol (1R,2R)2(methylamino)1phenylpropan1ol (1S,2R)2(methylamino)1phenylpropan1ol (1S,2S)2(methylamino)1phenylpropan1ol 9

10 Terbinafine hydrochloride (commonly marketed as Lamisil) is a synthetic allylamine antifungal from Novartis. Answer Q.28 based on the following structure and atomlabeling of Lamisil. 28. Which of the following description regarding Lamisil is incorrect? Lamisil contains a chiral nitrogen atom (N2). Lamisil contains a chiral carbon atom as C8. Lamisil contains both cis and trans C=C. Lamisil contains alkyne functional group How many chiral carbons are present on sucrose?

11 Mupirocin (Bactroban or Centany) is an antibiotic of the monoxycarbolic acid class. It was originally isolated from Pseudomonas fluorescens NCIMB Mupirocin is bacteriostatic at low concentrations and bactericidal at high concentrations. It is used topically and is effective against Grampositive bacteria, including methicillinresistant Staphylococcus aureus (MRSA). 30. How many chiral carbons are present on mupirocin? Continue to the Next Page 11

12 II. The 7 th reaction in citric acid cycle is the conversion of furamate into malate, a hydration reaction catalyzed by furamase. Provide an electronpushing mechanism for this reaction (Note: no need to involve furamase in the mechanism but use H + as the catalyst.). The resulting malate is in S configuration (assignment). Draw the specific structure of (S)malate. (10 points) Next Page: Periodic Table & pka Values 12

13 pka Values for Some organic and Inorganic Acids Acid Formula pka Conjugate Base Ethane CH 3 CH 3 51 CH 3 CH 2 Ammonia NH 3 38 NH 2 Ethanol CH 3 CH 2 OH 15.9 CH 3 CH 2 O Water H 2 O 15.7 HO Ethylammonium ion + CH 3 CH 2 NH CH 3 CH 2 NH 2 Bicarbonate ion HCO CO 3 Phenol C 6 H 5 OH 9.95 C 6 H 5 O Ammonium ion + NH NH 3 Carbonic acid H 2 CO HCO 3 Acetic acid CH 3 CO 2 H 4.76 CH 3 CO 2 Benzoic acid C 6 H 5 CO 2 H 4.19 C 6 H 5 CO 2 Phosphoric acid H 3 PO H 2 PO 4 Hydronium ion H 3 O H 2 O Sulfuric acid H 2 SO HSO 4 Hydrogen chloride HCl 7 Cl Hydrogen bromide H 8 Hydrogen iodide HI 9 I 13