Dr. Peter Wipf Chemistry 2320 – Sophomore Organic Chemistry Self-Test 1/7/08 Basic Chemistry Review Exam A. (40 points) Provide products for the following reactions: a) CH3OCH3NO2SO3, H2SO4 b) 1. HBr2. Me2NH c) O200 °C d) HgCl2, H2OCHEM 2320 Page 2 B. (30 points) Order the hydrogens HA, HB, HC etc according to increasing pKa. OHBHCONHDHAHEHFO C. (30 points) While watching a re-run of “The Brady Bunch” you get a text message from a class mate who has been under a lot of pressure recently studying for OChem 2. He would like you to draw him the structures of a naturally occurring (S)- and a naturally occuring (R)-amino acid in the extended conformations that clearly show the configurations at the alpha-carbons. Of course you are happy to help him out. Also list the common names and the 3-letter abbreviations of the amino acids you select.CHEM 2320 Page 3 D. (30 points) Propose a detailed stereoselective synthetic approach toward the following compound starting from cyclohexanone and using reagents with 6 or fewer carbon atoms. Mechanisms are not required. OHCHEM 2320 Page 4 E. (50 points) Propose a detailed mechanism for the following process (describe electron movements with reaction arrows). What is the name of this reaction? Also name key intermediates and the product. CONH2Br2, NaOHNH2H2OCHEM 2320 Page 5 F. (30 points) Propose a synthesis of the following compound from organic precursors not exceeding five carbon atoms. Clearly indicate the reagents that you will use to effect the transformations. Mechanisms are not required. EtNOCO2MeNEt OCO2MeCHEM 2320 Page 6 G. (50 points) ) What reagents would accomplish the following transformations (more than one might be needed)? a) OMeOHO b) NHMeONHMe c) SSHH d) HOOH e) HOOHOCHEM 2320 Page 7 f) OOH g) OO h) O i) H2N CH CCH3OHN CH CCH2OHN CH CCH2OHOOHHN CHCCH3OHOO2NNO2+H2N CHCCH2OHOH2N CHCCH2OHOOH j) HO OHHO OCHEM 2320 Page 8 H. (50 points) Predict the product(s) for the following transformations. Indicate stereochemistry where appropriate. a) BrKNH2, NH3 b) NH2NMe21. NaNO2, H2SO42. c) 1. SOCl22. NH33. Br2, NaOH4. H3O+OHO d) MeNHEtH++OHH e) HOOCOOMeOHcatalytic H2SO4CHEM 2320 Page 9 f) PhSH, THFNO2BrBr g) +OOO1. AlCl32. Zn (Hg), HCl3. PCl54. AlCl3 h) +OOOtoluene, 50 °C i) OOMeNH2 j) OPh!CHEM 2320 Page 10 I. (30 points) Suggest three different syntheses of cyclopentanecarboxylic acid. Each route should utilize one of the following reagents. Then use any number of steps and any other reagents needed. a) Br b) BrBr c) OCHEM 2320 Page 11 J. (60 points) The following sequence follows a strategy that complements Fischer’s proof of glucose. Fill in the missing reagents and structures (a) through (g). Use Fischer projections for all open-chain structures. Follow the hints in the parentheses. D-Glucose(a)(b)!-methyl-D-glucosideO2, Pt (a special reaction that oxidizes only the primary hydroxy group at C-6 into a carboxylic group)H+, H2O(c)(d)D-glucuronic acid(write open-chain form only)CHEM 2320 Page 12 NaBH4(e)gulonic acid(write open-chain form only)!-H2O(f)gulonolactoneNa/Hg(g)(write both pyran as well as open-chain form)CHEM 2320 Page 13 K. (50 points) Provide the major products for the following reactions: a) OH85% H3PO480 °C b) MeI1. Mg, Et2O2. CH3CHO3. H3O+ c) CH3H BrCH3HCH3O1. KI, acetone2. NaCN d) 1. BuLi2. HCHO e) NaBH4, CH3CH2OHHHOCHEM 2320 Page 14 L. (30 points) Predict the major products for the following transformation. Draw all appropriate chair-chair intermediates to clearly illustrate your choice of the configuration of the intermediates and the product(s). Answers that do not provide a logical rationale for the choice of product or that lack stereochemical details will not receive partial credit. Br2HHCHEM 2320 Page 15 M. (40 points) Draw the most stable conformation of cis-1-methyl-2-phenylcyclohexane and calculate the relative energy of all possible chair conformers. What ratio of the conformers would you expect based on these energy values?CHEM 2320 Page 16 N. (30 points) Assign all stereocenters in the following natural product: OOO OOHMeOOwortm anninAcCHEM 2320 Page 17 O. (40 points) Provide a detailed mechanism for the dissolving metal reduction of alkynes. Use arrows to indicate electron movement and name all important intermediates according to their characteristic electron count.CHEM 2320 Page 18 P. (30 points) Provide a complete mechanism for the following reaction. What is the name of the product? 1. B2H6, THF2. NaOH, H2O2, H2OCHEM 2320 Page 19 Q. (50 points) ) What reagents would accomplish the following transformations (more than one might be needed)? a) BrBr b) CHOO c) N NI d) OHOH e) OHCH2DCHEM 2320 Page 20 f) OHBr g) OHCH2ONa h) H i) j) OCHEM 2320 Page 21 R. (40 points) What is the major intermolecular force that connects the following molecules? Indicate the structural orientiation of an ensemble of 3 (three) of these molecules in the gas phase. Is there any preferred, regular orientation? Provide clear, short answers; if you list more than one force, or if the drawings are ambiguous, or if the structures are incorrect, no partial credit will be given. a) Acetic acid b) Carbon tetrachloride c) Acetone d) N-Methyl acetamideCHEM 2320 Page 22 S. (30 points) Suggest three different syntheses of 2-methyl-2-hexanol. Each route should utilize one of the following reactants. Then use any number of steps and reagents needed. a) O b) O c) OOCHEM 2320 Page 23 T. (60 points) Suggest a structure for a compound X, C4H8O, that fits the following spectra. Assign all signals in 1H and 13C NMR, as well as one peak in the IR spectrum (if you assign signals or peaks incorrectly, or if there are incomplete assignments in the NMRs, there won’t be any partial credit for the correct ones).CHEM 2320 Page 24CHEM 2320 Page
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