pset4_s05_update - Massachusetts Institute of Technology...

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Unformatted text preview: Massachusetts Institute of Technology Problem Set #4 Due: March 10, 4:00 pm 5.12, Spring 2005 1. Provide the product of each reaction shown below. Include stereochemistry. 1. BH3, THF 2. H2O2, NaOH CH2I2 Zn(Cu) H2 Pd/C Cl2 RCO3H warm, conc. KMnO4 H3O+ 1. Hg(OAc)2, EtOH 2. NaBH4 1. OsO4 2. NaHSO3, H2O CHBr3, KOH HI 1. O3 2. (CH3)2S Br2, H2O 1 2. Provide the major product of each reaction. 1. mCPBA 2. NaOH 1. BH3, THF 2. H2O2, NaOH H2, Pd/C Br2 1. Hg(OAc)2, H2O 2. NaBH4 2 3. Provide the best alkene starting material and reagents required to form each product. Br a) Br Br Br b) Cl Cl O c) O O d) O OH e) OH OH HO OH f) HO OH OH O g) O H 3 4. Provide all the possible products for the following reaction. Which product is more stable and why? HBr 4 5. Provide all stereoisomers that result from the following reactions. For b-f, indicate if the products are optically active (C), optically inactive/racemic (R), or optically inactive/meso (M). a) 1. O3 2. H2O2, H2O b) CH2I2, Zn(Cu) Hint: build a model! c) Br2, H2O d) 1. OsO4 2. H2O2 e) 1. BH3, THF 2. H2O2, NaOH f) Cl2 5 6. a) Draw the intermediate that results from the reaction of Cl2 with (E)-3-methyl-3hexene. b) Show the initial orbital overlap for the second step of this reaction. c) Explain why the nucleophile attacks the more substituted atom in the second step by drawing transition states. 6 7. Using what you know about the first step of ozonolysis, show the mechanism and product for the following reaction. H2C N N 8. Lactones, or cyclic esters such as the starting material shown below, are prepared by halolactonization, an addition reaction to an alkene. The following lactonization is a key intermediate in the synthesis of prostaglandin PGF2a. Draw a stepwise mechanism for this addition reaction. OH O OCH3 OH I2 NaHCO3 I OCH3 OH O O 7 9. Show the mechanism for each reaction. Ignore stereochemistry. a) HBr OCH3 b) O CH3 HBr O c) OH Cl2 8 10. Show the mechanism and major product for each reaction. a) HBr b) HBr 9 ...
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This note was uploaded on 11/27/2011 for the course CHEMICAL E 20.410j taught by Professor Rogerd.kamm during the Spring '03 term at MIT.

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