Chemistry 14D Winter 2017 Final Exam Part A Page 1 Please use the backs of the exam pages for scratch space. Please do not use the exam margins for this purpose. All reactants and solvents written above and below the reaction arrows are assumed to present in excess, unless otherwise specified (i.e., cat.). K use '' anywhere on this exam where appropriate. 1. (2) Complete this statement by adding no more than fifteen words: A carbonyl group is electrophilic because... 2. (3) Complete this reaction by writing the missing reactant(s) and solvent(s) in the box: 3. (6) Write a mechanism: C 2 2 C 2 4. (2) In lecture we learned of the three common carbonyl fates. In the space below write the name(s) of all of these fates that do not occur in the mechanism of question 3. If all of the common carbonyl fates are used write, "all are used". Questions 5 10 refer to this reaction: 2 5. (3) Write the major organic product of this reaction in the box above. Give extra thought to this answer, because a wrong answer for this question may cause you to write wrong answers for questions some below. Page 1 score =
Chemistry 14D Winter 2017 Final Exam Part A Page 2 6. (4) Complete each statement by adding no more than ten words in each case. The two reasons must be very different. (a) This hydrolysis reaction of question 5 cannot involve an enolate because... (b) This hydrolysis reaction of question 5 cannot involve an enolate because... 7. (3) In the box below write another molecule that undergoes hydrolysis at least as quickly as phosgene, and gives the same product as you wrote in question 5. 2 Same product as question 5. 8. (3) In the box below write another molecule that undergoes hydrolysis obviously more slowly than phosgene, and gives the same product as you wrote in question 5. 2 Same product as question 5. 9. (4) Complete each statement by adding no more than ten words in each case. The two reasons must be very different. (a) The hydrolysis reaction of question 8 is slower than the hydrolysis of phosgene in question 5 because... (b) The hydrolysis reaction of question 8 is slower than the hydrolysis of phosgene in question 5 because... 10. (8) For each reaction below, write the major product in the product box, then in the rate box write 'F' for faster if this reaction is faster than the reaction of phosgene with water alone (i.e., no 2 S 4 or a), 'S' if the reaction is slower, or '' if it occurs at nearly the same rate. Major product Rate (a) 2 S 4 2 (b) a 2 Page 2 score =
Chemistry 14D Winter 2017 Final Exam Part A Page 3 11. (10) Write a complete mechanism for this reaction: cat. 2 S 4 C 3 C 3 12. (3) In the box write the major product of the following reaction: 1. C 3 MgBr 2. 3 + C 3 13. (8) Write a mechanism for the formation of the major organic product of the reaction in question 12. 14. (3) The Weinreb amide shown below reacts with C 3 MgBr to form a ketone as the final reaction product. With this thought in mind, predict the major product (i.e., write it in the product box) of the reaction of the Weinreb amide with the alkyne anion shown below. If no reaction is likely, write "R" for no reaction in the product box. C 3 1. C CC 3 2. 3 + C 3 Weinreb amide Product Page 3 score =
Chemistry 14D Winter 2017 Final Exam Part A Page 4 15. (3) Complete this reaction for a likely synthesis of the Weinreb amide of question 14 by writing one structure in each empty box. 3 C C 3 C 3 C 3 16. (10) Imines are ubiquitous in biology, appearing in a wide range of chemical processes including vision, diabetes, and glucose metabolism. As an example of imine formation, write a mechanism for the following enzyme-catalyzed imine-forming reaction. For this reaction, Enz- is a weak acid and Enz: is a weak base. C 3 2 Enz-, Enz: C 3 17. (6) Consider the rate of the reaction in question 16 if acetone is changed to benzaldehyde. Complete each statement below by adding no more than fifteen words in each case. Be specific and precise. Benzaldehyde (a) ne factor that might make the imine formation reaction with benzaldehyde faster than the imine formation reaction with acetone is... (a) ne factor that might make the imine formation reaction with benzaldehyde slower than the imine formation reaction with acetone is... Page 4 score =
Chemistry 14D Winter 2017 Final Exam Part A Page 5 18. (3) Write the major product in the box: C 3 (C 3 ) 2 cat. 2 S 4 19. (2) In the box below each structure write the pk a of the indicated hydrogen atom. pk a choices: 23, 17, and 7. Each number will be used exactly once. 3 C 3 C 20. (3) The product of this reaction has molecular formula C 16 14. Draw the structure of this product in the box. C 3 a C 3 21. (8) Write the mechanism for this reaction: ac 3 C 3 C 3 22. (3) In the blank after concept, write the number of one exam question, such as 68(q), in which that concept occurs. If the concept occurs more than once write just one exam question number. If the concept does not occur anywhere on this exam write "99" in the blank. rganometallic reagent: Fischer esterification: Strong acid catalysis: Page 5 score =