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A CHM Version 2211 Exam 1 Summer B 2006 (Davidson) Name: UF ID: Directions: Put all of your answers on the answer sheet (last page of this packet). Only the responses on the answer sheet will be graded. Please be sure to put your name on the answer sheet as well as on the exam. You may separate the exam from the answer sheet. Turn in both the exam and the answer sheet. 1. (4 points each, 20 points total) Draw the structures for the major organic products for the reactions shown below. Be sure to indicate proper stereochemistry (using dashes and wedges) were necessary. a) O HBr (excess) b) CH3ONa O CH3OH c) Cl2 40 oC d) 1) Hg(OAc)2, CH3OH 2) NaBH4 e) NBS light 2. (4 points each, 8 points total) Nomenclature. Give the correct name or draw the correct structure for the following compounds. a) NO2 b) p-ethoxytoluene NH2 3. (4 points) Thymol, drawn below, is an aromatic compound that is found in the herb, thyme. Give the IUPAC name for thymol. OH 4. (10 points) The following ether reacts with one molar equivalent of HBr to form the product shown below. Write a detailed mechanism that shows how this reaction occurs. Be sure to show all of the important intermediates, including formal charges, and show the correct flow of electrons using curved arrows. + HBr (1 equiv.) O HO Br 5. (6 points) A synthesis of 1,4-dioxane can be accomplished by reacting 1,2-dibromoethane with ethylene glycol in the presence of an appropriate base. Br Br + base HO OH O O 1,4-dioxane This same synthesis can be used to make crown ethers, simply by controlling the ratio of reagents to form the larger rings. you Would expect to make the same crown ether if you used lithium hydroxide versus potassium hydroxide? Why or why not? 6. (8 points) Draw the kinetic and thermodynamic product for the reaction shown below, and clearly label which one is which. Cl2 (dark) 7. (6 points) The molecule drawn below undergoes an intramolecular Diels-Alder reaction to give a bicyclic product. Propose a structure for this product. 8. All attempts to synthesize cyclopentadienone yield only a Diels-Alder product. Cycloheptatrienone, however, has been prepared by several methods and is quite stable. O cyclopentadienone cycloheptatrienone O a) (5 points) Draw the structure of the Diels-Alder product formed by reaction of two molecules of cyclopentadienone. b) (5 points) How do you explain the marked difference in stability of these two molecules? (Hint: Consider any important resonance contributors.) 9. (6 points) Consider the molecule drawn below and indicate if it is aromatic, antiaromatic, or non-aromatic. Briefly explain your reasoning. B H 10. (4 points each, 16 points total) Provide the missing reagent(s) in the reaction scheme shown below. OH (a) O O (b) OH (c) (d) O H O 11. (6 points) Outline method for using a Williamson ether synthesis to generate enantiomerically pure (S)-2-ethoxybutane from appropriate starting materials. Extra Credit (4 points) Draw and label the HOMO and LUMO for 1,3,5-hexatriene. Exam Color _________________ CHM 2211 Exam 1 Answer Sheet Summer B 2006 (Davidson) Name: UF ID: 1a 1b 1c 1d 1e 2a 2b 3 4 5 6 7 8a 8b 9 10 a 10 b 10 c 10 d 11 Extra Credit ... View Full Document

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