1 of 9 Third Midterm Exam [Chapters 8-10 (Carey textbook)] CHE201A-C Professor Diver and Dr. Clizbe Nov. 21, 2014 Fall 2014 Version B (Exam duration: 1 h 30 min) NAME:______________________________________________ circle one: Dr. Clizbe or Dr. Diver and: Section ( A, B, C ) TA Name:____________________________ or CHE203 Page Total Possible Points (Possible Points per page) Points 2 25 3 20 4 15 5 30 6 30 7 20 8 15 9 Periodic Table TOTAL POSSIBLE: 150 YOUR TOTAL:_________ Molecular models are ALLOWED; calculators are NOT ALLOWED. No cell phones or extra paper will be provided. Fill out the exam in pen, use the back of the page if more room is needed. CHECK THAT YOUR EXAM INCLUDES ALL 9 PAGES.2 of 9 1. (30 pts) Circle the correct structure for each question. (5 points each). (a) Which of the following dienes will not react in the Diels-Alder reaction? (b) Which of the following nucleophiles is the strongest? (c) Which is the most reactive dienophile? (d) Which of the following molecules cannot be made by acid-catalyzed hydration of an alkyne? (e) Which of the following will have the fastest rate in an SN2 reaction?3 of 9 (f) Which of the following molecules represent an allylic halide? (circle all that apply) 2. In the following hydration of 1-butyne, intermediate A is initially formed, but was not isolated. Draw the final isolated product (product B) and provide a detailed mechanism showing each individual step going from intermediate A to product B. For full credit, use the arrow formalism to show electron movement (15 points).4 of 9 Molecular Orbital Theory 3. (15 points) Answer the following questions based on 1,3-butadiene. (5 points each) (a) Draw the HOMO of 1,3-butadiene. (b) Draw the LUMO of 1,3-butadiene. (c) Using the relevant orbitals, draw the transition state of the Diels-Alder reaction between 1,3-butadiene and ethylene.5 of 9 4. (30 points) For the following reactions, indicate if the mechanism goes by SN2, SN1, E2 and/or E1. If more than one product is formed from the same pathway, state which product is major. Show stereochemistry where applicable. (6 points each). (a) (b) (c) (d) (e)6 of 9 5. (30 points) Write the organic product(s) for each of the following reactions. Provide stereochemistry where applicable. (6 points each) (a) (b) (c) 1. NaNH2, NH32. CH3Br3. H2, Pd, CaCO3 lead acetate, quinoline (d) (e)7 of 9 6. Reaction Mechanism (20 points) (a) Circle the major product (5 pts). (b) Using the arrow formalism to show electron movement, provide a detailed mechanism showing each individual step of the reaction mechanism. Be sure each step is charge balanced and mass balanced. For full credit you must account for the use of all reagents and explain the formation of both products in the reaction (15 pts)8 of 9 7. Synthetic Pathway Show how the following conversion can be accomplished in good yield. More than one step will be needed. Provide the reagent(s) needed for each step. Also, include the product of each step. (Mechanism, transition states, mechanistic intermediates are not needed) (15 points)9 of