University of Texas, Rio Grande Valley - CHEM 2325 Homework - II (CHEM 2325-03) Fall 2016  1)What are the basic differences between SNAr reaction with SN1 and SN2 reactions?      Why SNAr reactions are not considered either SN1 or SN2: Explain considering chlorobenzene as an example               What is benzyne? Discuss the mechanism of formation of aniline from chlorobenzene

University of Texas, Rio Grande Valley - CHEM 2325

Homework - II (CHEM 2325-03) Fall 2016

 1)What are the basic differences between S_NAr reaction with S_N1 and S_N2 reactions? 

2. Why S_NAr reactions are not considered either SN₁ or SN₂: Explain considering chlorobenzene as an example

3. What is benzyne? Discuss the mechanism of formation of aniline from chlorobenzene. 

4. Explain the stability order of 1-butene, cis-2-butene and trans-2-butene.

5. Draw the orbital diagram of BENZYNE. 

6. Why 2-chloropropene is formed as the sole product in the reaction between propene and HCl?

7. Explain with a clear diagram why secondary carbocation is more stable than primary carbocation?

8. Discuss the mechanism of the electrophilic addition of water to 1-methyl cyclohexene. 

9. How TBME can be synthesized from the electrophilic addition of alcohol to alkenes? 

10. Draw the mechanism of bromination of cis-2-butene.

11. Why is hydroboration regioselective? Explain the mechanism considering HydroborationOxidation reaction to propene. 

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14. Explain with suitable examples the concept of E-and Z- alkenes. Is there any difference between Cis/Trans with E/Z ?

15. Cis-2-Butene has a higher boiling point (4 ⁰C) than trans-2-butene (1 ⁰C) — Explain.  

16. How can you correlate the melting points of oleic acid, linoleic acid and linolenic acids with their double bonds? 

17. What is ‘mercurinium ion”? When does it form? 

18. What is keto-enol tautomerism? Explain with the example of Curcumin. 

19. Hydroboration-Oxidation of an internal alkyne produces ketone whereas the same reaction for a terminal alkyne yields aldehyde — why? State the rule associated with this. 

20. Oxidation (KMnO4 or ozone) of unsymmetrical internal alkynes produces two carboxylic acids whereas under the same condition terminal alkyne produces one carboxylic acid — Explain.