Chemistry 263 Quiz 1/Exam 1 Practice Spring 2018

Transcription

1 Chemistry 263 Quiz 1/Exam 1 Practice Spring 2018 The following practice contains 36 questions covering chapters 14, 15, and 16 in Loudon and Parise s rganic Chemistry, 6 th edition. Quiz 1 will contain 20 questions valued at 1.5 points/question ( bonus questions), and exam 1 will contain 30 questions valued at 3 points/question ( bonus questions) Name: 1. What is the IUPAC name for the compound shown? a. (S,E)-3-chlorohex-4-en-1-yne b. (R,E)-3-chlorohex-2-en-5-yne c. (S,E)-3-chlorohex-2-en-5-yne d. (R,E)-3-chlorohex-4-en-1-yne e. (R,E)-3-chloropent-4-en-1-yne 2. Addition of excess to 2-methyl-3-heptyne produces I: 2-methyl-3,3-dichloroheptane II: 2-methyl-2,3-dichloroheptane III: 2-methyl-4,4-dichloroheptane : 2-methyl-3,4-dichloroheptane : 2-methyl-3-chloroheptene & II b. I & III c. II & d. e. All of the above

2 3. Which of the following would not be a successful method for preparing 5- methyl-1-hexyne a. 1) NaN 2 (2 mol), liq N 3 2) N 4 b. C CNa c. Li C C d. 1) NaN 2 (3 mol), liq N 3 2) N 4 e. 1) NaN 2 (3 mol), liq N 3 2) N 4 4. An unknown compound, A, has the molecular formula C n oxidation with hot aqueous potassium permanganate, A yields C 3 C 2 C and (C 3 ) 2 CC. Which of the following structures best represents A? a. b. c. d. e.

3 5. 2-pentyne will not react with a. 2, Pt b. 2 c. N 3 d. 2 S 4 e. KMn 4 (aq) 6. What is the major product for the following reaction sequence? 1. 2, Lindlars catalyst 2. 2, C 4 a. enantiomer b. c. enantiomer enantiomer d. e. enantiomer

4 7. Which free radical would be most stable? I II III 8. Which carbocation would be most stable? C 2 C 3 C 3 C 3 C 3 I II III

5 9. Which of the following pairs do not correspond to resonance structures? I and II and III and and e. N/A; All are examples of resonance structures 10. Which of the following dienes would be least stable? I II III

6 11. Estimate the stabilization energy for 1,3-butadiene using the heat of hydrogenation data given Table 1. eats of ydrogenation for Selected Compounds Compound Moles 2 (kj mol -1 ) 1-Butene Pentene ,3-Butadiene trans-1,3- Pentadiene a. 13 kj mol -1 b. 15 kj mol -1 c. 28 kj mol -1 d. 239 kj mol -1 e. 112 kj mol Which of the following symbols is used to communicate the intensity of absorption in the U-visible portion of the electromagnetic spectrum? a. b. c. d. e. 13. Which of the following is the most energetically favorable U transition for 1,3-butadiene? a. n * b. n * c. 2 3 * d. * e. 1 4 *

7 14. Which of the following can undergo a Diels-Alder reaction? I II III & II & III & d. I, II, & 15. From a Diels-Alder reactivity standpoint, which of the following is the poorest choice of dienophile to react with 2,3-dimethyl-1,3-butadiene? I II III 3 C C 3 3 C C 3 e. 16. A reaction under kinetic control will yield predominately a. the most stable product b. the product that can be formed in the fewest steps c. the product whose formation requires the smallest free energy of activation d. the product of greatest potential energy e. the product of least potential energy

8 17. A reaction under thermodynamic control will yield predominately a. the most stable product b. the product that can be formed in the fewest steps c. the product whose formation requires the smallest free energy of activation d. the product of greatest potential energy e. the product of least potential energy 18. Which of the following is the correct Diels-Alder adduct for the reaction shown? C C 2 C 3 C C C CC 3? CC 3 CC 3 CC 3 CC 3 CC 3 I II III CC 3 CC 3 CC 3 CC 3 CC 3

9 19. Which Diene and Dienophile would give the pair of enantiomers shown? I II III 20. We now know that the two Kekule structures for benzene are related in the following way: a. They are each equally correct as a structure for benzene b. Benzene is sometimes one structure and sometimes the other c. The two structures are in a state of rapid equilibrium d. Neither of the two structures adequately describes benzene; benzene is a resonance hybrid of the two e. More than one of the above

10 21. f ückel's requirements for aromatic character, which is the only one waived in the case of certain compounds considered to be aromatic? a. The ring system must be planar b. The system must be monocyclic c. There must be (4n 2) electrons d. The ückel number of electrons must be completely delocalized e. None. All of these rules must apply in every case 22. The anticonvulsive drug carbamazepine is shown below. It is not considered to be aromatic across all 3 rings. The most likely reason for this is a. The ring carbamide (urea) N cannot adopt an sp 2 configuration b. There is no way to achieve (4n 2) electrons c. The system has more than one ring d. The 3 rings are not coplanar e. More than one of the above 23. Which of the following is aromatic? I II III e. None of the above

11 24. Which of the following is aromatic? N N B N S C C 33 C 3 II II III 25. Please name the following compound Name: 26. Which of the following is aromatic? N 2 N N S N N I II III

12 27. In which case are the non-bonded electrons not a contributor to the aromatic system? S N N I I II III e. N/A; non-bonded electrons contribute to aromaticity in each case 28. EAS mono-bromination of aniline at the para position requires which of the following in addition to bromine? a. A bulky deactivating group b. A Lewis base c. A Lewis acid d. U light e. Nothing 29. Reacting toluene or styrene (vinylbenzene) with conc. KMn 4, -, & followed by 3 would yield which of the following results? a. A reaction in each case, with the same principal product b. A reaction in each case, with different principal products c. A reaction with toluene, but not with styrene d. A reaction with styrene, but not with toluene e. No reaction in either case 30. What is the chief product of the [relatively slow] Friedel-Crafts alkylation of benzene with 1-butene and F? a. Butylbenzene b. 2-phenylbutane c. 2-methyl-1-phenylpropane d. t-butylbenzene e. 2,2-diphenylbutane

13 31. What would be the product of the following reaction sequence? i) P 5 ii) C 6 6, Al 3 iii) Zn(g),, heat? I II III 32. Which of the following would be most reactive towards ring nitration? a. Benzene b. Toluene c. m-xylene d. o-xylene e. Benzoic acid

14 33. Which of the following is the principal product(s) of the reaction shown? S 3 2 S 4 C S 3 3 S S 3 I II III d. Approximately equal amounts of I & II e. Approximately equal amounts of I & III 34. What is the major product of the following reaction? 1 equiv. N 3 2 S 4, heat? 2 N N 2 I II N 2 III N 2 2 N

15 35. What would be the major product of the following reaction? Al 3? I II III 36. Which of the following is not a potential synthetic route to benzophenone (diphenyl ketone)? a. b. c. d. e. C 6 6 C 6 5 C Al 3 2 Cr 4 (C 6 5 ) 2 C acetone 1. 3 (C 6 5 ) 2 C=C 2 2. Zn, Ac PCC Ph 2 C C 2 2 N/A; all of the above will yield benzophenone