Chem 14D Spring 2010 Garg Midterm 2 Review Practice Problems The exam is cumulative although there will be an emphasis on the material that was not included on Exam 1 This includes the following Chapter 9 Alcohols Epoxides Vollhardt 9 1 9 4 9 6 9 7 9 9 Convert alcohols to halides reaction conditions and mechanisms Ether Synthesis base or acid mediated inter or intra molecular epoxides Epoxide reactions under acidic conditions mechanism regioselectivity stereochemistry Epoxide reactions under basic conditions mechanism regioselectivity stereochemistry Drawing mechanisms for carbocation rearrangements Chapter 12 Reactions of Alkenes Vollhardt 12 1 12 8 12 10 12 12 For each of the following be sure to know the general reaction mechanisms regiochemistry and stereochemistry where applicable Catalytic hydrogenation Addition of hydrogen halides Markovnikov etc Addition of halogens Addition of halide and OR or OH Alkene hydration using acid oxymercuration reduction hydroboration oxidation Epoxidation Dihydroxylation Ozonolysis Chapter 13 Alkynes Vollhardt 13 6 13 8 Alkyne reduction Addition of hydrogen halides Alkyne hydration Chapter 14 Diels Alder 14 8 but skip endo section General reaction Mechanism Electronic properties of substituents Stereospecificity Chapter 15 Reactions of Benzene Vollhardt 15 8 15 13 Electrophilic aromatic substitution of benzene for the following processes halogenation sulfonation nitration alkylation acylation PRACTICE QUESTIONS 1 1 Draw the major product for each of the following reactions and state if the reaction is Markovnikov Anti Markovnikov or Not Applicable a Me Me Br HBr Markovnikov b Me Me OH 1 OsO4 OH 2 H2S Not Applicable c Me 1 Hg OAc 2 H2O OH Me 2 NaBH4 Markovnikov d Me Me 1 BH3 OH 2 H2O2 NaOH Anti Markovnikov e Me Me Pd C H2 Not Applicable f Me Me Br Br2 Br Not Applicable 2 2 Draw the major product for each of the following reactions a Cl OH O NaH b Me Me OH OH 1 OsO4 2 H2S c Me Me OH OH 1 MCPBA 2 NaOH d Me Me OH SEt 1 MCPBA 2 NaSEt e Me OMe OH Me 1 MCPBA 2 H MeOH 3 3 Provide reagents for the following transformations a H2 Lindlar catalyst b H2 Pd C c O H2SO4 H2O HgSO4 d 1 Cy2BH 2 H2O2 NaOH O e Br HBr Br f 1 n butyllithium Br 2 Br2 4 Rank the following in order of reactivity in the Diels Alder reaction with 1 3 butadiene 1 being most reactive 3 being the least reactive CF3 3 1 2 4 5 Rank the following in order of reactivity in the Diels Alder reaction with ethylene 1 being most reactive 3 being the least reactive NC MeO 1 3 2 6 Predict the product of each of the following transformations Be sure to show relative stereochemistry where applicable a heat b MeO2C CO2Me heat CO2Me CO2Me c heat d CN NC CN NC CN CN heat CN CN e O H heat H H O H O H 5 7 a Draw an arrow pushing mechanism for the following transformation O heat O N N Me Me O N Me b Draw a transition state for the reaction shown in part A O N Me 8 Provide reagents for each of the following transformations a Br2 FeBr3 Br b fuming sulfuric acid SO3H c HNO3 H2SO4 NO2 MeBr AlBr3 Me d e O O Cl Me AlCl3 Me 6 9 Predict the product of the following reaction and draw an arrow pushing mechanism for the transformation O MCPBA H H Cl O O O H Ph Ph 10 Draw an arrow pushing mechanism for the following transformation O O O3 O O O O O O O O O O O O O 11 Propose a mechanism for the following transformation HO Br HBr Br HO H Br H2O H2O 2o carbocation 7 3o carbocation much more stable Synthesis Problems Propose syntheses of the following compounds using standard reagents and any of the carbon building blocks shown in the Chem 14D toolbox You are encouraged to think about mechanisms and retrosynthetic analysis although you are not required to show either in your solution Chem 14D Toolbox O O Me O O 12 O H Br O Br H O O H O Br2 O H O Br O Me H Me heat H O O 13 Me H O heat Me Br heat Me H2 Pd C H 8 H O 14 Br Br O 1 O3 heat H 2 H2S H O Br OH MeMgBr PBr3 Br OH 15 HO 1 NaBH4 EtOH 2 PBr3 O O HO Mg BrMg Br OR HBr heat NKG 5 9 10