CHE 331 Molecular Science II

Transcription

1 CE 331 Molecular Science II Final Exam Form 1 Thursday May 12, :00AM 10:45AM 180 Point Exam 1. Write your nine digit University ID number in the space provided and then bubble in each of the nine digits. 2. Print your name and sign your answer form using the spaces provided. 3. Questions 1 to 20 are 5 point multiple choice questions. Bubble your answers on the answer form. Questions are short answer questions with points as indicated. Write out your answers in the indicated place on the answer form. The reaction chart and tables of IR stretching frequencies and 1 and 13 C NMR chemical shifts are on the last pages.

2 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 2 of Six different protonation states of the amino acid lysine are shown below. The pk a of the carboxylic acid group is 2.2. The pk a of the protonated α-amine is 9.0. The pk a of the protonated side chain amine is Choose the structure that represents the main form of lysine found in your blood, which is buffered at a p of 7.4. D 2. Choose the major product of the following reaction. 3. Choose the most stable conformation of trans-1-ethyl-3-methylcyclohexane. C F

3 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 3 of Supposed you carried out the hydroboration of 1-methylcyclohexene. Choose the correct product or products. A. An equal mixture of products 1 and 2. B. An equal mixture of products 2 and 3. C. An equal mixture of products 1 and 4. D. An equal mixture of products 3 and 4. E. An equal mixture of products 1, 2, 3 and 4. F. Product 5 only. B 5. An unknown compound with the formula C has the following infrared spectrum. Identify the compound. The compound s 13 C NMR spectrum shows four peaks. E

4 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 4 of Choose the major product of the following reaction. Li 3 C C 3 2 C 3 C 3 C 3 C 3 A B C D E F F 7. Choose the answer that has the following compounds located correctly in the separation scheme. A. The acid is in flask 1, the amine is in flask 2, and the hydrocarbon is in flask 3. B. The acid is in flask 1, the amine is in flask 3, and the hydrocarbon is in flask 2. C. The acid is in flask 2, the amine is in flask 1, and the hydrocarbon is in flask 3. D. The acid is in flask 2, the amine is in flask 3, and the hydrocarbon is in flask 1. E. The acid is in flask 3, the amine is in flask 1, and the hydrocarbon is in flask 2. F. The acid is in flask 3, the amine is in flask 2, and the hydrocarbon is in flask 1. B

5 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 5 of Choose the major product of the following deuterium exchange reaction. 9. Which set of arrows is the best representation of the correct mechanism for the following reaction? C 10. ow many of the structures shown below are aromatic? C A 1 B. 2 C. 3 D. 4 E. 5 F. 6 B

6 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 6 of Which of the following drawings best represents the ighest ccupied Molecular rbital (M) of protonated benzene? A 12. Choose the order that has the indicated bonds arranged correctly with respect to increasing bond strength. i ii iii A i < ii < iii B i < iii < ii C ii < i < iii D ii < iii < i E iii < i < ii F iii < ii < i C 13. Which of the following comparisons of acid strength is incorrect? A

7 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 7 of Name the compound shown below. A. (R,Z)-3,6-Dichloro-3-octene B. (R,E)-3,6-Dichloro-3-octene C. (S,Z)-3,6-Dichloro-3-octene D. (S,E)-3,6-Dichloro-3-octene A 15. Five structures below have the same Index of ydrogen Deficiency (ID). Select the structure that has a different ID. F 16. Choose the order that has the following compounds arranged correctly with respect to increasing K eq of their hydration (the compound with the greatest % of the gem diol should be on the right). 17. ow many stereoisomers are there of the following compound. E A 3 B 4 C 5 D 6 E 7 F 8 D

8 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 8 of Select the best method to synthesize 3-methylcyclopentanol. A 1. B , Na B 1. g(ac) 2, 2 2. NaB 4, Na C Br 2 2 D Cl 2 E 1. B , Na F Select the major product of the following reaction. E 20. Using only the oxidation and reduction reagents shown below, complete the following synthetic transformation. F A. 1 only B. 2 only C. 1, then 3 D. 2, then 3 E. 1, then 3, then 2 F. 2, then 3, then 1 D

9 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 9 of Draw a good resonance representation of the major product of the following acid-base reaction. (5 pts) 22. Draw a good resonance representation of the major product of the following acid-base reaction. (5 pts) 23. Give the major product of the following reaction. (5 pts) 24. Give the major product of the following reaction. (5 pts) 25. In the following roadmap, compound A gives 2,5-dimethyl-2-hexanol upon reaction with aqueous acid. Reaction of A with osmium tetroxide gives a meso diol (compound B). Draw the structures of compounds A and B. (6 pts)

10 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 10 of The product of the following synthetic scheme is said to be a component of soy sauce. Draw the structure of the major product. (8 points) Li 1. PCC 1. Li S(C 3 ) zonolysis of compound E leads to a single product (F) with molecular formula C xymercuration-demercuration of E leads to the same product (X, C 7 14) as hydroboration of E. Draw the structures of compounds E and F. The 1 NMR or compound F is shown below. (10 pts) 1. g(ac) 2, 2 X C NaB 4, Na or 1. B , Na E (C 3 ) 2 S F C

11 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 11 of Thionyl chloride can be used to dehydrate an amide to make a nitrile. Draw a curved arrow mechanism for the reaction shown below. Make sure to clearly show all bond breaking and bond making steps. (10 pts) 29. Draw a curved arrow mechanism for the rearrangement shown below. Make sure to clearly show all bond breaking and bond making steps. (10 pts) 30. Propose a synthesis of the compound shown below. All your carbon containing starting materials must be of four carbons or less. (10 pts)

12 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 12 of Choose one of the following two problems, A or B. Indicate clearly which one you are working. No extra credit will be given for working both problems. Complete this problem for 6 points A. Sabinene is a monoterpene isolated from nutmeg. Propose a biosynthetic pathway for its formation. Myristica fragrans terpinyl cation Sabinene terpinyl cation Sabinene r

13 CE 331 Molecular Science II Spring 2016 Final Exam Form 1 Page 13 of 14 Complete this problem for 12 points (Your exam will have a total of 186 points.) B. Borreria verticillata is a traditional medicinal plant that grows in tropical regions. It produces the sesquiterpene Gaiene shown below. Propose a biosynthetic pathway for its formation from farnesyl pyrophosphate. Borreria verticillata Farnesyl-PP PP Gaiene redraw PP

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