Chem 634Exam 2December 10, 20073 hoursProf. FoxYour Name_______________________________1. Provide reagents for the following transformation. More than one step may be required.Do not write mechanisms.2.5 points eachabcdPh HOMeOOOOOOPhOCO2MePh HOPh2. Provide the products of the following transformations. Do not provide mechanisms (2.5 ptseach)abcPhOMeO1) DIBAL2) H3O+DON CH3IPd(0), Et3Ncat PdCl2, cat CuCl2, O2, H2OdTFAHOHO1) MeC(OEt)3, cat EtCO2H, Δ2) mCPBA (1 equiv)OEtO2C3. Indicate if the following would or would not proceed as written. If it will not proceed aswritten, provide the structure of the product that would be formed instead along with a briefexplanation. 4 pts eacha.b.Ph1) O3, PPh32) KOHPhOc.OOO1)2) TsNH–NH2, Δ4. You require a synthesis of 5 from aldehyde 1. Unfortunately, the addition of acetylide 2 toaldehyde 1 is not selective: it gives a mixture of diastereomers 3 and 4. Luckily, diastereomers 3and 4 are separable by chromatography, and can be separately converted into 5. 20 ptstBuOOtBuOOHtBuOOH134tBuO5EtO2Cprocedure Aprocedure B1)Li2) separate diastereomers2a. Outline a stereospecific synthesis of 5 from 3 below. b. Provide a stereochemical model that explains the stereospecificity of the key transformation inyour proposed synthesis4. You require a synthesis of 5 from aldehyde 1. Unfortunately, the addition of acetylide 2 toaldehyde 1 is not selective: it gives a mixture of diastereomers 3 and 4. Luckily, diastereomers 3and 4 are separable by chromatography, and can be separately converted into 5. 20 ptstBuOOtBuOOHtBuOOH134tBuO5EtO2Cprocedure Aprocedure B1)Li2) separate diastereomers2c. Outline a stereospecific synthesis of 5 from 4 below. d. Provide a stereochemical model that explains the stereospecificity of the key transformation inyour proposed synthesis5. Provide a detailed, arrow pushing mechanism. 12 ptsOTMSONMeOCO2tBuCO2MeHF+NCO2tBuCO2MeHOONNPhOHOS SMeAIBN, Bu3SnHΔOH6. Provide a detailed, arrow pushing mechanism. 20 pts7. Outline a multistep synthesis 20
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